I used to have an aircard with Verizon and paid $60/month for that service. Then, I switched to a Storm, dropped the aircard, and went from $60/month for the aircard, to $15 for tethering via my Storm. No regrets there, at all.

Then, about 2 weeks ago, I bought TetherBerry(.com) and dropped the $15 a month for tethering and just use TetherBerry now for connecting my laptop to the Internet via my Storm.

TetherBerry has been virtually flawless, so far. If tethering works through his ATT Pearl without paying any extra, go for that. If it doesn't, I would definitely try out TetherBerry before paying ATT.