Quick review:
The Kindle DX has finally made it worth owning a Kindle for the purpose of reading technical books.  The native PDF rendering works wonderfully.  Also, many of the books below, if not free in the first place, were significantly cheaper than the dead tree equivalent which resulted in a large cost savings.  Finally, the weight of the Kindle, roughly 18oz, is significantly lighter to carry than all of these books (which only represent a few of the 100+ PDFs on the device which only occupy a few percentage of the total storage capacity).

Worth the $500?  I’d say so.

(Click any of the images for their original 12MP image)

_Why’s Poignant Guide to Ruby

Golden Gate Ruby Conference Wrap-up

The Well Grounded Rubyist

Random Lambda Calculus PDF

Pragmatic Programmers – Programming Cocoa

Peepcode – Git Internals