(from OP) Thanks for all your great, prompt suggestions and laughs. We went again to the Verizon store and my son's decided on the Droid Charge. I just saw the announcement about free phones on Amazon on Monday so it will be even more within our budget (I was going to give it to him as a birthday present, but that seems a bit chintzy if that announcement pans out!)
P.S. Suuperflie, I totally agree with you that my 15-year old doesn't need a smartphone and "kids nowadays" are really spoiled. I tried to talk him into a feature phone, but told him if he wants a smartphone he'll have to pay for the monthly data plan (as well as the $10/month phone line fee). That's why he's been mowing several lawns each week and putting it into a savings account. He is convinced that I'm the meanest Mom in the world because "everybody's" parents get them a cell phone and pay for their monthly fees.
(I do think I'm pretty mean - we get our kids their first bike, but after that they have to buy them if they want better ones; they have to pay for their cell phone plans, if they want a computer they have to save for it and buy it, if they want to drive they have to pay for their car insurance - pro-rated from our insurance plan, and buy their their own car if they don't want to borrow ours, etc. We do pay for their college education as long as they maintain a B-average though, so I think it's fair. It has made them into quite good deal shoppers, Craigslist, E-bay, and they've learned how to buy computer parts and build their own computers so it has been educational for them)
