Did a minor upgrade to the Powerbook last night and added 512mb of RAM. RAM is the least expensive and highest return investment you can make on any computer system.
Installing the RAM is as easy as removing 4 screws, sliding the stick into place until it clicks, then making sure the clips are locked into the notches on the side of the stick and putting the cover back on. All told it took me 10 minutes with the longest part of that time trying to get the damn plastic package the RAM came in open.
Overall the performance boost is quite noticeable and VERY welcome.