I currently have a 20" iMac C2D 2.16Ghz w/ 1GB memory. If I buy a 1GB ram stick, can I just install it in the RAM slot? I don't know too much about this stuff. Is this something that will work? http://cgi.ebay.com/1GB-RAM-for-App...7QQihZ013QQcategoryZ80202QQrdZ1QQcmdZViewItem Thanks in advance.