Ask YC: When and how did you start showing off your product?

Our project is on target for an August 1st release, and we're planning on recruiting beta users in our local area using old fashioned methods like "talking to people" and "putting up posters".

Our application is geographically bounded -- that is, it's no fun if there aren't any other users in your region. Because of that problem, we've had trouble deciding on the best strategy to reach a wider audience.

So, even if it doesn't apply directly to our problem, for added insight I'm asking other startup founders -- at what point in your startup process did you start looking for a wider audience? Was there any rhyme or reason to how they came to you? What sorts of channels did you try to advertise yourself through?