I can empathize with scope-creepers, though. I, too, often find myself wanting to add something to a project I'm working on. Right now, I'm forcing myself to stop adding new things to Balloon Ghost. I want to finish the game this weekend, and I simply can't do that if I decide to add a completely new element to the game.

The good news is that it's easy to decide against a new feature when you realize that less is more. For projects, the original idea is often the best part. Adding extra things to it won't make it better, and it will usually just make it worse. The trick is to ignore the feeling that the product isn't complete without that one little thing. Chances are it will not only survive without it - it will be superior without it.