Hi
Looking to upgrade the memory in iMac 2.ghz Core 2 Duo.  I am interested in experiences people have had upgrading to either 2 or 4Gig in terms of performance improvement.  I am also interested in alternatives to the expensive memory from the Apple Store.  I saw some 2gig Kingston sims for $107 and some cheaper Cosair sims (2 x 2 gig sims) for $150. 
Cheers
Richard