30 Rock is rolling out quite a few guest stars for the upcoming season – the latest stars to join the hilarious NBC show are Gossip Girl stars Leighton Meester and Blake Lively.

Look for Leighton Meester and Blake Lively to appear on 30 Rock during November sweeps. The pair will play former classmates of Liz Lemon’s. Get ready for a great flashback sequence (can’t wait to see Tina Fey back in the day) as we find out that she was really a mean girl in high school.

The episode will also feature Leighton Meester and Blake Lively’s characters fast fowarded 20 years at Liz’s high school reunion (buzz is that 30 Rock wants Lively’s older sister, Robyn, to play one part).