I have successfully upgraded the RAM in my Mac Mini to 2 GB. My computer originally had 1 GB installed at purchase. I spoke to the folks my local Apple Store and they wanted over $250 to replace my memory with new chips. I thought that was insanely high and chose not to do that.
I decided that I’d try to install the new RAM myself. One thing about the Mini is that it isn’t meant to be opened. There are no screws or tabs to open the case. You have to pry it open to get inside, which effectively voids your warranty. I decided to take that chance. I bought two 1 GB chips from Crucial for an amazingly cheap price of $48 total. I successfully installed my new memory last night, and I am now up and running without any problems.
This was actually my second attempt at upgrading my memory. Last week, the chips that Crucial first sent me were high density RAM chips, and my Mac couldn’t use it. I think the company mistakenly thought I had the latest Core Duo 2 Mini, which apparently does support the high density memory chips. This was simply a misunderstanding and the company corrected the mistake.
If you own a Mac Mini and want to do this yourself, check out the following how-to videos on YouTube. If neither of these suit your fancy, there are a lot more videos and instructions on YouTube, and elsewhere online.