http://www.sbsh.net/products/pocketbreeze/
It does a lot, if you are someone that manages your time, appts, contacts etc. (or you want to be) It will work with PI and Fusion, but you can also use it over the stuff that comes with your axim, or by itself.
I'm finding it useful (and pretty ;p hey, there's a lot to say about making the screen look all nice and stuff)
Not having been someone that used planners, pdas etc before, it's... sometimes hard to just sit there and DO it, but it's pretty cool once it's done and you can see what is coming up, what you have time for... and appts. you won't forget.
Download the trial and give it a try, try to use it fully so you get a good idea of what it can do for you and if it's actually useful For you. :)