Why Bebook ! check it out !
1. It has full hierachical folder structure support.
2. It uses a regular Nokia battery (BL-4C/BL-5C); Easy to find a replacement.
3. Long battery life, more than two weeks if I keep it open during the day hours and read several pages per day.
4. Support for PDF, DOC, WOLF, MP3, HTML, TXT, CHM, FB2, Djvu, PNG, TIF, GIF, BMP, JPG, PPT, EPUB, LIT, PRC, MOBI. it'd support MOBI DRM.
5. It's open，unlike the Sony readers or Kindle.
6. Regular software updates and very active community.