Not wishing to hijack Phil's thread (but I am ). I've decided to stick 512MB in my iBook (bringing it to 768). I looked at crucial.com and found a 512MB SO-DIMM for £82. Looking at the specs I can get a similar Corsair module for £58. Now, I've never upgraded laptop memory before. I've stuck with Corsair for last few upgrades and I haven't had a failure yet. They both offer lifetime guarantees (for what they're worth) which would you guys go for?