I recently got a Motorola Droid & have used Aldiko and and looked at Wordplayer. Both are adequate for short reading sessions & often the small size and backlight for these type of reading sessions is a plus. The battery life is not sufficient for longer sessions anyway. I usually need to charge mine every night.
The really nice thing about it is that it incorporates most of the PDA functions I want so I have now combined two devices into one. Also the software "PDAnet" by June Fabrics
allows internet tethering
(i.e. I can use my Droid as a 3G modem for my laptop). They also have a version of PDAnet for the iPhone, the Palm Treo & Centro, Windows Mobile phones and the Blackberry.