Astak EZReader supports: ADE (Adobe Digital Edition), PDF, TXT, PDB, DOC, HTML, FB2, LIT, MP3, EPUB, PRC, WOL, CHM,
PPT, TIF, PNG,GIF, RAR, ZIP, DJVU, JPG, BMP.
I believe the PDB is PalmDOC, not eReader. And some PPT features probably won't work, but it should be fine for just reading presentations rather than watching animated ones.