There is an option in iSilo (4b2) to customize the buttons of the palm.
Here is a button layout I find especially comfortable (Zire 71):
1st button: Full screen
2nd button: Auto-scroll
Jog: Hyperlinks
3rd button: Back
4rd button: Default
I should also mention that the third button is assigned in the OS5 to run iSilo.
Such layout allows me not to get the stylus out when I'm coming back to read a document. I can also quickly browse links without using the stylus.
My only gripe is that in the book selecting list of iSilo the jog/keys are inactive. So my only way to select/open a book is by the stylus, shame
.