Britney Spears put in treadmill time at Bally's again yesterday. While we're still not sure how hard she could be working out with the sunglasses on, it probably helps her chances of becoming the gym's spokeswoman. Hopefully that job prospect is looking up, because it seems everyone jumped the gun a little about Brit making another appearance on How I Met Your Mother. The interest from the network is still there, but there's no script and nothing has been set in stone just yet. Luckily, however, Sarah Chalke has signed on for another episode, which can only increase Britney's chances of reprising her role as the obsessive receptionist.