reddit is basically an IRC server for the web, with voting.

The cleverst thing they have done is also entirely simple. By making all thread replies to your posts appear in your inbox as personal messages, and highlighting the orange icon, it successfully encourages users to make reasonably deep replies to those that bite.

This seems to generate interesting thread content very quickly.

My only gripe is the lack of resolution in the voting system (ala /.). Meme overload is a real problem when browsing reddit.