$500 out of Pocket - Clarification

[Judy Swann]

Good evening (11:36 pm, 8/22/07). My name is Judy and I'm new to this forum. In my area I'm seeing signs written sometimes by hand, sometimes "professionally" done, that says, "Buy a home with only $500 total out of pocket! Credit no problem". I do not see how this is possible, with closing/appraisal costs and the like. I want to know what exactly does that mean--if anyone on the forum knows, please edify me if you don't mind.

Thanks to all for your time.