Done a blog post thing about a couple of battery saving ideas for your Android phone. Nothing revolutionary but maybe worth a look.
Linky thing (http://www.deadmen.co.uk/forum/entry.php?19-More-go-from-your-Android-phone)
TBH swapping to FroydVillain 1.5 did a lot for me. It is the only ROM with JIT-optimisations made specifically for the Hero. This helps a lot. It also has a much more efficient frequency manager than SetCPU etc.
I also supplement with Locale which powers down all unnecessary stuff during nights, turns off wifi when outside home area, reduces brightness way down after 11 pm etc. I get around 2-2,5 days now on regular battery, sometimes close to three, sometimes a little more than 1, when gaming on it.
I now get 7 full days on the extended battery :)