"accesskeys" with Firefox

Q: Did you know, how to make use of what gets defined in HTML through the accesskey attribute of the a tag?
A: You have to press some Modifier + the defined accesskey.
All the HTML generated from my DocBook files defines access keys for navigating to the statically previous and next page, the home page, and to climb up the tree.
For the Firefox on openSUSE Linux the Modifier is Alt+Shift,
for the Firefox on OS X Snow Leopard the Modifier is simply Ctrl,
for Google Chrome on OS X Snow Leopard the Modifier is Ctrl+Alt.