Letters to Cleo's Kay Hanley and Folks from American Hi-Fi with Hannah Montana
I'll be damned; commenter Jaime was right. In a case of art imitating life, Hannah Montana's backing band contains Letters to Cleo badasses Kay Hanley and Stacy Jones -- the latter of whom was in American Hi-Fi with Jamie Arentzen (who's also in Hannah's band and is now also playing with Butch Walker).
Hanley, of course, sang for Rachel Leigh Cook in the Josie and the Pussycats movie -- a story about a teenybopper group that became huge stars, albeit through nefarious means.
Here's Letters to Cleo covering Cheap Trick's "I Want You to Want Me," from one of my favorite teen flicks of all time, 10 Things I Hate About You. Scroll past Heath Ledger making out with Julia Stiles to get to the clip (although I'm not sure why you wouldn't want to watch...er...)