Is it possibe/advisable? My iMac which I bought in store at Brent Cross has one 512mb module and an empty slot (I thought that Apple provided macs with matched pairs..but whatever...). I'd like to get a 1gig module for the empty slot, yes I am aware of dual-channel, but I think I'll benefit from more memory for running Photoshop etc. I'd like to be able to avoid forking out for the expensive Apple memory. Also, where are the best places to get RAM in the UK? There's not much in the Guide for the UK (I'm avoiding Crucial like the plague btw).