Identifying Plastic
A chart with what the recyclable numbers / plastic ids mean - e.g [2] is HDPE, which is high density polyethylene. There's also a table of properties and common usage (and repair method), and a flow chart helping to id unknown plastics.

Cabinet Making Tips, Hints and Ideas
choked with ads, but some very worthwhile, mostly simple wood and shop work tips.

ShouldExist || Good ideas, prototype reviews, group projects
This looks like a great forum, discussing all kinds of (mostly) practical solutions to everyday problems.. Along the same lines as the global ideas bank (url?. .seems like I blogged this too not so long ago).
I entered here, looking for screen OCR software. Kleptomania, the main recommendation, is cool but doesn't perform well enough for me to justify the ticket.
The discussion of biofuels, and biodiesel in particular was also a good one. This stuff needs to happen.