How to remove leftover Band-Aid stickiness off my phone?

I had a few band-aids stuck onto the back of my iphone 3g (I know, I know, bad idea; but they were these super adorable Hello Kitty ones!). However, I have decided to get a new case that is sort of transparent, and I didn't want the Band-Aids to get in the way of the pattern so I peeled them off. However, now there is that awful sticky residue- you all know what I'm talking about, right? Sometimes it stays on skin when you peel off a bandaid, too....anyways, please help me! I made a bad mistake and now I don't know what to do (haha, it sounds like I'm pregnant...). Please help! I need to get this gross sticky stuff off!