This one's not jQuery-specific but futzed with my mind yesterday and should probably be on any javascript developer's radar:

http://www.breakingpar.com/bkp/home.nsf/0/87256B280015193F87256C85006A6604

If you're ever wondering why parseInt isn't working with '08' or '09', this is why. Ue parseFloat instead.

[2 cents] Argggh! And thanks much to the original poster. If I hadn't found that post I'm not sure how long it would have taken me to narrow down that bug (I was working on a js function for reading data from a USB credit card swiping gizmo and the routine to parse the data wasn't working for months '08' and '09'). Good find.

PDF-based cheatsheet for common (ok, most) jquery functions. Broken into same categories as the jquery docs, includes 'overrides' and return types.

http://www.gscottolson.com/jquery/jQuery1.2.cheatsheet.v1.0.pdf

[2 cents] Worth it just to have the lesser-used functions at hand, assuming of course you have room on your desk for paper (ack!). If only my printed copy were clickable so I could get examples for each. Rassafrassin.... someone ought to design a world wide web.