Britney Spears' return from insanity begins with a guest spot on How I Met Your Mother this Monday night. She'll play Abby, a sweet-but-not-so-smart receptionist at a doctor's office (doctor played by Sarah Chalke). Six items from Britney's on-screen wardrobe will be auctioned off next week to benefit the Natural Resources Defense Council. Available merchandise include a Juicy Couture dress (I didn't know receptionists could afford Juicy Couture!), and a Nanette Lepore dress and cardigan.

The auction is sponsored by CBS and 20th Century Fox Television, so I don't think Britney had anything to do with it or with the organization that will receive the money from the items. The auction begins Monday night, right after the episode airs.

There are several clips of Britney's appearance on HIMYM on CBS' YouTube channel. They're super short and completely out of context, but I posted two of them after the jump in case you're interested: