So, I signed up with Virgin Mobile. The entire web buying experience was flawless, other than being constantly confronted with pictures of happy, goofy teenagers being cool. It probably helps them sell the service to their target market, but I also think that 20 years from now, 40-year-olds will look back on those pictures the way we middle-agers look back at the way they depicted us. Really, go look at the site.
The upshot: $100 for the phone, which includes $20 of usage. (There was a different model for $80, but I wanted vibrate ringing.) 25 cents a minute, dropping to 10 cents after 10 minutes. I ordered the phone one morning, they shipped it FedEx overnight for free, and I got the phone the next morning. I have to "top off" my phone with at least $20 every three months. This means that I'm paying about $7 a month and I got a reasonably good phone (it has vibrate mode and reasonable battery life) for $100. Initiating the service was easy, although I was again confronted with happy, goofy telephone folks who were being cool. I thought I was going to be invited to a really rad party.
For someone who doesn't use a cell phone much, this pays off completely in under six months.