If you are using Calibre on a computer to handle your eBook library, then the Android App "Calibre Library" (
see this link) works great for me for doing wifi browsing and transfer of books onto my Galaxy Tab.
Not quite as neat a solution as the integrated browsing my iPod Touch has with Stanza, but still far better than plugging in by cable.
So basically I Use Calibre to organize on the pc, "Calibre Library" to move books to my Tab, and Aldiko to read.
I did a writeup on my Galaxy Tab
here on my site. The bottom lists some of the apps I've found to be "a cut above".