Need more RAM?
Yesterday, I finally got around to upgrade my 17" PowerBook to 1GB of RAM. Do I need the extra 512MB? Probably not. Do I notice a speed increase after? I don't think I use enough RAM-intensive programs to know the difference.
On the other hand, I also took my friend's Blueberry iBook (circa 1999) for a RAM upgrade. A store employee walked up to look at the toilet-seat wonder, and mentioned what excellent condition it is in. I told him the owner hardly ever used it after she bought it, and that's why the battery is dead. Then another employee said that the fact it can still be turned on is a miracle, though it took forever to boot up in Panther.
I chose the 256MB module for the iBook, so the store assistant slid out one of the two 64MB cards from a RAM slot to replace it with the 256MB, for a total of 320MB. I noticed a speed increase immediately upon restart. Mac OS X 10.3 booted up much faster. Moving around the Finder is snappier, too. The real difference, though, is when I opened iPhoto. Whoa, I could actually navigate through rows of pictures in near real-time, something it took forever to do before the upgrade.
Even though this iBook is limited by a 300MHz G3 and 4MB of VRAM, increasing the RAM surely is the best thing you can do it if you plan to run Panther on it. I'm impressed.