If for the DS, no. If for the PS3, maybe. There is a Karma Power in the PS3 version that letsyou go back to CAS (Create A Sim) for five Karma points, I think. If you're referring to The Sims 3 for PC, here are the steps:
http://answers.yahoo.com/question/index?qid=20110624153552AAgbK5A
For Xbox 360, if it's not Pets, I don't know. I might look it up often so I might update this post if I find any further information. Hope I helped!
I'm now in love with the little "despicable" Minions from Despicable Me. I saw the second film a few weeks ago and loved it and now I adore the Minions as well. They're too cute! Who doesn't love Minions? And I might not have a new sig and avy up for a while since I'm saving Images to my 3DS Camera. Look on Examiner.com to read what they're saying in the first film's credits.