one of the best viewer-programs around
-- for those of you on the p.c. platform --
is "ybook", by simon hayes.  and it's free...

it even has a hookup with the p.g. catalog,
so you can download e-texts from inside it.

ybook also lets you wrap a book you've written
in a standalone executable .exe, which is nifty...

http://members.iinet.net.au/~simonh/spacejock/yBook.html

-bowerbird