I've just done a RAM upgrade for an Intel Mac Mini. Don't listen to people who tell you that it's hard. It isn't hard. Silly people like to be harbingers of doom. And Apple likes to charge you a few hundred dollars for something that you can do yourself for the cost of the RAM and a few simple tools.
You need a 1.5" putty knife, a flashlight, a long jeweller's screwdriver, and a pointed scribe or small flat-head screwdriver. I bought the putty knife at Rona and I already had the other things.
Oh yes, and you'll need some new RAM. I bought a pair of 512 MB SODIMMs from EBay. They were pulled from a MacBook. :o)
Pop open the case and remove the top half (less than 30 seconds).
Remove the four corner screws for the hard-disk base-bracket (a few minutes).
Unclip the AirPort antenna (15 seconds).
Unclip the short, jumpered cable from its socket at the front of the computer. (under two minutes).
Lift the optical drive+hard disk+base bracket out and lay the assembly down gently (under 1 minute).
Unseat and remove two RAM SODIMMs (a few minutes).
Install new RAM SODIMMs (under one minute).
Put it all back together (10-15 minutes).
The Intel CPU benefits significantly from having more RAM. The upgrade procedure for the Mac Mini is simple. Don't be dissuaded by the nay-sayers.