I upgraded my iMac from 2GB to 3GB so I could install Lion. My iMac is a late 2006 model Core 2 Duo at 2.16 GHz.
Package from Amazon.
The Crucial DIMM.
Instructions for accessing the RAM are thoughtfully printed on the underside of the stand.
Two original 1GB DIMMS with one removed (Samsung).
New memory inserted.
Reboot with 3GB RAM 🙂