My son turned 13 last week. His request since last year has been to have an iPod Touch for his birthday. Since his sister got one for her 13th birthday, we acquiesced and got him one.
That has meant hours and hours of his playing on it and adding free apps and texting with his cousins (a couple have iPod Touches and one has an iPhone) and then, upon getting a $15 iTunes gift card as part of a gift on Saturday, I'm guessing he has added in some apps he has to pay for. We'll see how well he manages his funds!
He is not a self-regulator for fun electronics, so I've finally had to start putting some limits. Going all out for a few days is okay, but at some point, reality needs to be lived. ;)
That said, if anybody has some great educational apps recommendations that a 13yo would enjoy, fire away! :D