Bummer, Duchess.
I discovered (by accident, kind of) the other day that there *is* a search function in the Sony Reader software for the PC. So you can't do a search on the Reader itself, but you *can* search a book in your library via your PC.
I did something with my Reader that I'm pretty pleased about. I needed to give my NaNo novel a full re-read after making a bunch of changes to it. So I converted the file to a .pdf and loaded it onto my Reader.
I had to make hard-copy notes of the edits I wanted to make in the Word file (btw, I discovered you can load Word files onto the Reader, too). But it was really convenient to be able to read the manuscript on the Reader. And think of the trees I saved!
Yes, you saved some lovely trees. 
).
