I just bought a Sony PRS505 and absolutely love it. The screen quality is outstanding and it has really put back enjoyment into my reading.
I wanted to get more eBooks onto my Sony so I developed some software to convert from Project Gutenberg books into Sony LRF format.
You can try it out at www.coolfreebooks.com
Please remember that this is being provided free of charge although I will obviously respond to emails etc I cannot 100% guarantee that all enhancements will be implemented.