Haali Reader is an e-book reader most of you have probably never heard of before. It's available for Windows Mobile devices and supports the FictionBook XML standard (which is quite common in Russian-speaking areas; Roger posted some
more details on the FictionBook format). Other neat features include ClearType support, fullscreen and landscape mode, dictionary support, automatic hyphenation (Russian language only), and PRC/PDB files support.
The latest version can be downloaded from
here.