I just finished watching Bob's presentation. The best introduction to Erlang I've seen, so if you've been wondering why I'm pointing to Erlang so much, watch this and you'll understand.

Bob Ippolito's weblog

Links for Downloading slides and code for Bob Ippolito's Erlang presentation at C4. It's quite helpful to have the slides open in your browser while you watch the video since they aren't always visible while he speaks.

Presentation slides from Ande's talk at linux.conf.au 2007. Explains the problem with shared-state concurrency (ie: threads and locks) pretty convincingly, and explains how Erlang does a great job of avoiding the problem and how it performs so well.

Followup on the link to Andre Pang's talk, here's the LtU post about it. Lots of good info in the comments.