New Kismet release, 2011-01-R1.
Lots of bugfixes (netxml reference, 802.11d, mac80211 on legacy cards, client preferences, client display options)
Ruby network API and example clients
Wifi NIC performance shoot-out tool
WPA Migration Mode detection
GPS logging in PPI pcap files
Per-capture source per-network and per-client signal tracking
Source and (some) packages available at the Kismet site
Ubuntu 32 and 64 bit packages also available on the Kismet download page, since Ubuntu seems to have stopped updating years ago and seems determined to ship code several years out of date.