The Squad: Perfect Cover by Jennifer Lynn Barnes
Bayport High School's varsity cheerleading team is composed of the most beautiful, the most athletic, the best-dressed, and the most popular girls in town. Toby Klein may be a black-belt in karate and an expert computer hacker but she has no school spirit, dresses badly, and has a tendency to beat up the guys who pick on her younger brother. She is horrified to be invited to join the cheerleading team until she learns that the girls are actually highly trained spys for the United States government Their cover is perfect - who would expect anything from a cheerleader?
What follows is lots of great clothes and accessories that double as spy gadgets, lots of girl bonding and gossip, lots of wildly improbable technology (a huge spy complex under the school). The reader really needs to suspend disbelief for Squad books (their is mention of Charlie's Angels but it reminded me even more of the Teletoon show "Spy Girls), but this looks like a fun series for those who are happy to do so.