muPDF

No lag. Nuf said.

http://www.mupdf.com/

OverDrive Media, Nerd-Rage

http://www.overdrive.com/software/omc/faq.asp

Seriously, no WMA audio support for Android OR Apple? This is a bit like when I was reading a book about design (The Shape of Things) and the binding started to come apart..."hmm, what conclusions might we draw from this?"