Chat with other OSCONers in the IRC channe: irc://irc.openprojects.net/oscon (aka server irc.openprojects.net and channel #oscon). Some good IRC clients are Snak (OS X), BitchX (*nix) and BersIRC. If you just want to follow along check out the IRC Chat Logs.
For information about the programs and people, check out the O'Reilly Conference Page. I'll be linking to notes, press and blogs from the sessions pages, so email me if you have something to be included.
O'Reilly themselves will be taking notes, photos and blogging on the O'Reilly Conference News Page.
Finally, I've keeping track of people I'm watching for session notes over at the list of bloggers.