Electronic book software

I downloaded the Kindle Reading App for my computer and phone. I may read a few books on it. But I was interested in what is available for reading books in other formats. It seems that epub is the default and open standard for publishing electronic books.

Here is a nice review of various electronic readers.

I have installed Calibre which, amongst other features, allows you to convert a pdf to epub. It is not really designed as a reader but does fine. I have also installed the EPUBReader plugin for Firefox, but have yet to try it.