Steve, welcome to MobileRead, glad to have you here.
In addition to the Sony Reader, I also have a Palm powered Samsung i500 cell phone that I have read on for many years. I started with Palm Reader although lately I have switched to using Mobipocket Reader as my main reader on the Palm. I also have Plucker installed so that I have three ebooks active at any one time.
I find the Mobipocket Reader to be more flexible and and more feature rich than Palm Reader plus it reads all of my old PDB files as well as the the great library of Mobipocket ebooks available here for free. I am a great fan of the Sherlock Holmes stories and keep a copy of Harry's
Complete Sherlock Holmes on the phone for those times when you want something to read but don't want to start another full length book. It is beautifully formatted and proofed better than any of the paper copies I have of the stories.
If you have any questions, just ask.