After having the same Mac laptop -- my familiar, friendly, 266mhz, G3, "wallstreet" powerbook -- for over 8 years, I finally decided the time had come to move on.
I went out and got myself a 1.42 Ghz G4. Not only upgrading my hardware, I've moved from using Mac OS X 10.2, Jaguar, up to 10.4, Tiger.
What a difference!
I wasn't really all that disturbed by the "slow" performance of my wallstreet. The big thing that motivated me to move was the increasing amount of interesting-looking application software which requires Tiger.
I'm having fun with the new software, maybe I'll write about some of it here, but the performance increase is really wonderful. It's like a cloud has lifted and now I can see.