I have several projects coming up soon for public release, both commercial and open source. The projects are all downloadable, not web apps. I've worked on them alone and would like to get feedback during a beta period, but I don't currently have a large audience (though the markets are large). What are the best ways to get participation in the betas? Are there any existing sites or communities that specialize in software testing that I can reach out to? At this point, I'm specifically looking for technical testers who aren't intimidated diving into the code and can help spot security bugs, logical errors, etc.
Edit: I'm looking for websites or communities similar to Invite Share. Invite Share itself would be perfect, but there doesn't seem to be any public information about how to submit a beta.
While Joel's article on running a beta is helpful, I wonder if there isn't an existing community available for beta testing of any sort, technical or user. As a self-taught and sole developer, I don't have a lot of technical contacts that would be appropriate approaching for testing. I did propose a Beta Testing site in Area 51 a few months ago, but it seems as if it either got buried, there wasn't a whole lot of interest, or it's a poor fit for StackExchange. If you know of existing testing communities, sites like InviteShare, or other ways to get testers, please share.