The author of this post is our reader: Cyryl.
To install FBReader in your phone just find it in Android Market and then... just install ;)
FBReader is easy to use and I thing that there is no need to write about something that simple. I can only tell, that you can add the bookmarks and using search engine inside without any trouble, what is actually very useful.
There's also no problem to install FGReader in Windows Mobile, Maemo or even Ubuntu. Just type in the console:
sudo apt-get install fbreader
FBReader works with oeb, epub and fb2 formats, but you can create ebook from another filetypes such as txt, rtf, pdf.
To do this, just install the Callibre:
sudo apt-get install calibre
More information: fbreader.org, calibre-ebook.com