i'm always idling in #mklinux on freenode. i'm on a bunch of mailing lists: linux kernel, some debian lists, lists for linux and netbsd ports to different archs (alpha, amd64, sparc, mips, pa-risc).
i used to be all about usenet, but not since around '98, a little after the aol influx. spam ruined usenet.
for web sites: slashdot.org, arstechnica, realworldtech.com (hard core stuff about cpu design), storagereview, anandtech, the register and the inquirer for industry gossip.