I have managed to reduce the amount of stuff that i have to carry around by getting an O2 Atom, similar to the other O2's mentioned above, but it has a 2MP camera, which comes in handy just for the shots to show that there should be a cache here, but there isnt
It also runs Ozi CE nicely, which allows me to save on carrying the laptop (well i still take it out sometimes, some of the maps are too large to load into any PDA).
I can export straight out of GSAK onto the SD card, and then read the logs through internet explorer. If i get really stuck and want to look at more logs i can use GPRS to look at the GC.com site as long as i have mobile phone coverage.
My GPSr is a 60c, which gives me the mapping capabilities as well.
The only other thing i carry when im going out for a whole day of caching is my canon S2 IS.
Just by getting the Atom, its saved me from carrying the mobile phone (since it is now my mobile), and its improved the effectiveness of carrying a PDA, just by its ability to do more than one thing at a time (my old PDA was an IPAQ 1910)