I got old IPaq 3630 (32mb, ppc2000) with cf memory reader + additional battery extension card. (with 128mb cf memory)

Both of batteries on IPaq and battery card dies very quick(only up to 1~2 hours), but other than that it's still perfectly working device.

Nowadays I got Treo600 to take care every PIM stuff I need, so I wonder is there any useful area that I can put my IPaq into.

I tried use this as GPS Navigation but due to OS and memory issue, it wasn't successful.

Any good ideas?