I have 5GB in my Mac Pro right now, but I'm saving for two more 2GB sticks. When I manage to get them, I'll use four 2GB sticks and try to sell the two 512MB sticks that originally came with the machine.
My other Macs:
MacBook - 512MB, but 2GB is on the way
2 MDDs - 2GB each
Pismo 900 - 1GB
iBook 900 - 640MB
My other Macs:
MacBook - 512MB, but 2GB is on the way
2 MDDs - 2GB each
Pismo 900 - 1GB
iBook 900 - 640MB