I just upgraded the memory on our 6 year old Dell Dimension 4600 to 2gb. It runs a lot faster now. It'll run even better after I reformat the hard drive and re-install Windows.
As a result of the memory upgrade, I have 2 x 256mb of PC3200 DDR memory for anyone that can use it in their PC. Some PCs have 4 memory slots so if you already have 2 x 256mb, you can add two more and double your memory. It's very easy to install.
PM me or respond here if you can use it