Upgrading memory

How much difference will I notice if upgrading the memory on my Macbook from 2gb to 4gb? Is it a difficult DIY job? I assume it invalidates the warranty if doing it?

I don't do much in the way of editing but do a lot of DVD burning/coverting DVD to iPhone, that sort of thing.

Depends on what you do with your MacBook, but you should notice a difference. It's really easy, you just need a little screwdriver. It doesn't invalidate the warranty - there's even a little diagram of how to do it under your battery.

http://support.apple.com/kb/HT1651

Yes, you should see a difference.

I bought my 4GB before even buying my macbook. when mine gets here, i'll swap memory before i boot it haha. The more RAM the better, especially if you wanna run XP within Leopard via parallels or VMware