The second, is that PDF display on the Kindle 2 necessarily requires making the text very, very tiny. That, or using the device in landscape mode and viewing half a page at a time. Not too pleasant, especially when there are so many materials I'd like to have on hand in PDF format. Especially those I've downloaded from OReilly's Safari service.
In this latter regard, the Kindle DX is awesome. No longer do I have a thumbdrive filled with PDFs that I've been meaning to read. Now, as often as I can, I move them onto the DX, named appropriately and read them when I get a moment.
Here's a command that is a life saver. It merges multiple PDFs into a single larger one while preserving pretty much every aspect.
gs -dNOPAUSE -sDEVICE=pdfwrite -dBATCH \
-sOUTPUTFILE=newpdf.pdf a.pdf b.pdf c.pdf etc.pdf
Kindle DX, plus PDFs, I'm so happy now.
Oh and it reads books too :-).