More RAM is probably your least expensive and most effective upgrade. If you're running XP, 1 - 2 GB of RAM will make a noticable difference. Vista is more of a memory hog, but if you're not already running Vista, don't burden the machine with it.
If the machine has only two RAM slots, your least expensive upgrade would be to look for the best deal on a 512 MB or 1 GB DIMM. If you find a great deal on 1 GB sticks, and want to max it out, buy two, and sell the 512 MB stick that's now in the machine.
You probably won't have any problem mixing a PC3200 (333 MHz) stick with the current PC2700 (266 MHz) stick, but it will run at the lower speed. If the BIOS will recognize PC3200 RAM, you'll get even more performance by using only RAM of that speed.
Other things to buy as you find them on sale:[bulliet][*]A good, padded carrying case with pockets for accessories.
[*]A comfortable USB mouse, wired or wireless.[/list]
Another REALLY good upgrade would be an external hard drive about the same size as the one in the machine and copy of Norton Ghost or Acronis True Image to "clone" the drive to the external drive.
On my desktop, I have a second drive mounted in a
mobile rack, and I
use Ghost to back up my drive. If my main drive becomes corrupted or infected by a virus, I can clone my last good backup back to the main drive. If the main drive fails completely, I can switch the backup drive to be the main drive and keep stepping without having to re-install everything.
You can't install a 3.5" drive in a laptop, but if the drive becomes corrupted or fails, you can use it to restore everything to running shape, either to the original drive or a replacement, if necessary. For example, I just got a great deal on a 160 GB driver for my laptop. I Ghosted the original 40 GB drive to an external drive, installed the new drive, and Ghosted the backup drive to the new one in my laptop. It booted perfectly with no hassled.
Hope that helps.
