The first book I purchased was A Meeting at Corvallis.
I had just gotten my 505 and couldn't find the MMPB of Corvallis anywhere. I logged on to Sony's store and grabbed it up in LRF format. I was amazed when I was reading it within ten minutes.
Amazed at the ease of use, I purchased three more books to fill my reader.
And now five readers later, the digital shelf has grown exponentially out of control.