Just switched in the last week to a Powerbook G4 12" as my web and general 'stuff' machine. I really like it so far, and haven't found too many problems.
The first 'difficulty' was getting access to my companies windows shares though. Here's how I managed to get around some of the samba hitches ... Connect to network. I connect to a wireless usually, and make sure you can see the internet. Create a VPN using PPTP if you are connecting to a Microsoft VPN server. At this point you may be able to see shares on the windows network. I couldn't sadly. OK TURN OFF IPV6. I have no idea why this is on, but turn it off and try the VPN again. Now try doing the 'Connect to server' option in Finder. If you can connect to a windows share name, try the windows share name with the appropriate domain added to it. NT seems to be pretty smart about adding mycompany.com to windows names, allowing DNS resolution if something gets funky with the CIFS stuff.
Anyway, now I can connect great to my desktop machine and pull files off it.
Remote Desktop Connection
Google for this, and download for OSX from the Microsoft site. Works excellent.