eBook Reader alternate to Acrobat?

[Darwin]

Siouxdax, If you've already got Adobe Acrobat Pro installed, look no further than Adobe Reader Speedup (NB this DOES work with both the Reader and the full Acrobat package, despite the title). I used this with Adobe Acrobat Pro 5 and with Reader versions 6 through 9 and it makes a HUGE difference.

Highly recommended 

[vinayakjoshi]

- not without first registering for membership, it seems.
Does it even work off-line?

It does. The thing that I like is that you can bookmark the page you are on as well as annotate the book. It stores this information outside the PDF so this works even if the PDF does not give you the rights.