One of the advantages of working here at TechWeb is that the company will provide me with an activated BlackBerry phone with the added benefit of never having to fill out an expense report for it. Woo-hoo! But, if I want to move my existing cell phone number to that BlackBerry, the company's fine print is clear that I will never get the number back. In order to keep that number active so people don't lose track of me, my only choice is to do so at my own expense. But, with all the crazy wireless plans out there, what's the least expensive option? I made some calls to find out.By now, you're probably asking "David!!! What's the big deal? Sooner or later, you'll probably give up your existing number anyway." Actually, I hope not. I want to keep my number because it's one digit away from my wife's number. This makes our numbers easy to remember for friends and relatives. But more important, they're easier to remember for our young children. Every night at bedtime, we play a memory game where they are asked what our various phone numbers are.

My diabolical plan is to somehow keep the old number active without using it at all and to program its voice-mail message to tell inbound callers to call my new number (or, if I feel like paying extra, I can forward the calls). But what's the cheapest way to do this? I called AT&T, T-Mobile, Sprint, and Verizon Wireless (my current carrier) to see which of the four major carriers offered the best solution. Here's what I found out.

After a few calls, it became clear that the least expensive wireless calling plan was going to run me around $30 for a month. I really didn't care how many minutes came with the plan, what the deal was with nights and weekends, or how many calls I could make to other customers of the same wireless carrier. So, when the various customer representatives tried to explain to me why the $30 plans (and in the case of some carriers, $40) were such a good deal, it wasn't resonating with me.

After calling the last of the four major wireless carriers, I hung up the phone in a relatively disillusioned state. At bare minimum, it was going to cost me $360 per year to keep my personal cell phone number assigned to me.

That's when the lightbulb went off. What about those pre-paid phones I keep hearing about -- the ones that make it difficult to track terrorists? Could they be an option? As it turns out, they are. But, despite having described the "business problem" I was looking to solve, none of the customer representatives I spoke with asked "Have you thought about a prepaid phone?" I suspect, based on my experience and how I was transferred between customer care representatives, that the monthly calling plan people and the prepaid phone plan people at each of the carriers are different people who have a limited understanding of what the other has to offer. Ultimately, this is probably causing all the carriers to lose customers.

All four major U.S. wireless carriers offer prepaid "plans." But you might not know it from visiting their Web sites. The plans don't exactly jump out at you. Depending of which of the four carriers' sites you go to, digging for something as simple as a phone number to call can be a chore, too. Maybe it should be a law that telecommunications companies must prominently display a toll-free number on their home pages. Or maybe every page on their sites.

The interactive voice response (IVR) systems with their labyrinths of menus are a joke, too. "Press 2 if you want information about our Premier Plan." I don't even know what the premier plan is or why I'd want information about it. How about "Press 1 to bypass these stupid menus and speak to a customer care representative now?" The old "zero trick" to get you straight to a human hardly works anymore. Now, it's a puzzle. "Hmm...which of those options is most likely to lead to another option that will eventually get me to a human?" I rarely guess correctly.

Once you get to a human (if it's not past your bedtime and you don't have a blister on your forefinger), the first thing you hear is, "Hi, my name is Lilliandra. Can I have your 10-digit phone number starting with area code first." What happened to good old phone manners? "Hi, thanks for calling fill in the carrier name here. My name is fill in the mashup of a name you've never heard before. How can I help you today?"

Eventually, I found my way to a human at each of the four carriers. Some of these humans had the energy of a snail and I could swear one was stoned judging by how long it took for him to complete each word. He said "yeah" once and it felt like the longest "yeah" I've heard since one of those endless nights in someone's college dorm room back in 1980 (with Pink Floyd playing in the background). The only difference is that he didn't burst into a fit of laughter half-way through each sentence.

Of the four carriers, Verizon Wireless had the worst news for me. Since it is my current wireless carrier, it has no way of transferring my number from one of its monthly plans to one of its prepaid arrangements. Originally, I thought Verizon Wireless would be the easiest solution. I could keep my phone, change it over to a prepaid arrangement, and maybe even get one statement that covers both my wife and me (as we do now).

The other three carriers had a different story. Yes, they told me: Not only could they transfer my existing number to one of their prepaid arrangements, it was also possible to go the other way if I ever changed my mind. "Excellent!"

But of those three, only one stood out as the clear winner in terms of saving me the most money: T-Mobile. The key questions when it comes to prepaid minutes are (1) What's the fewest number of prepaid minutes that can be bought at one time and (2) How long is it before they expire? Some expire in 30 days. Some 90. Others a year. Then you have to do the math. For example, AT&T has a $25 plan whose minutes expire after 90 days. Compared with what you'd pay annually under a regular monthly plan, the $25 plan every 90 days (for a total of approximately $100 per year) represents a significant savings.

Sprint has a completely different Web site for its prepaid stuff. Sprint's prepaid brand is called "Boost." Not only were Sprint's prepaid options the most confusing to me, the customer representative I spoke to was the least interested of the four in helping me sort through the options. The more I spoke with him, the more I felt like with Sprint, it's hard to go the prepaid route without ending up in the equivalent of a monthly plan. He kept telling me about how it was going to cost me $1 per day for this, that, or the other thing. At $1 per day, I might as well go with a $30 monthly plan from one of the carriers.

Surely, Sprint must have a regular prepaid arrangement that doesn't involve a $1 day (like what the other carriers have). This is when I learned about a "Boost card" that I have to go buy in a store and scratch some numbers off. It sounded like a lottery ticket, only more complicated. Eventually, I was told the minimum investment is $20 with an expiration period of 90 days. That works out to approximately $80 per year.

AT&T had the best customer care representative of the lot. She immediately understood my problem, went straight to the best (and aforementioned) solution (she even did the math for me) and when I said I thought T-Mobile had a better deal, she said (my approximation of her words) "Well, let's go shopping online." I was stunned. Together, we browsed T-Mobile's Web site. I read off a URL to her and when she had some difficulty with all the characters, I asked if she had access to Google. She did and I took her down the same path I used to find the exact page that I was looking at.

There, on that T-Mobile page, in the section called "Pay As You Go", she clicked the same "Expand to Learn" link that I did, and she spied the same plan I was looking at: the one with a minimum investment of $10 that takes 90 days to expire. The total annual cost worked out to be $40 (plus the one time cost of a $6 SIM card to insert into one of the AT&T-compatible GSM handsets I have laying around here somewhere). In her words, "That's an awesome plan. We don't have anything that can match that. If I were looking to do what you're looking to do, that's what I'd go with."

'Nuf said. T-Mobile, you're about to get my business.