I got expose (well, mission control at least, I am running Lion) and dashboard widgets to work just using the built in Keyboard Shortcuts preference pane. I was able to map them to function keys and activate them on my HHKB, did not try with any other boards. I tried mapping a range of keys to brightness up/down but none would have any effect on my apple external monitor (while the apple aluminium keyboard changes screen brightness on this one just fine) there is a cat sleeping on top of the laptop right now who does not like to be moved, so I cant check if it does it on the internal screen, but when he moves I can try.
a very expensive cat bed indeed, I think he likes it because it is warm.