Options for Upgrading 17" iMac

[xXriderXx7]

Hi.
For Christmas I am looking to upgrade my iMac.
I am going to order a 2 GB stick of Crucial RAM, maxing out my system at 3 GBs.
As far as I know, this is the only safe, non warranty voiding modification I can do.
Is this true?
If not, is there any upgrades you'd recommend, preferably something to do with graphics?

Thank You

 

[robbieduncan]

That's it in terms on safe upgrades. The only other things you can change are the harddrive and optical drive, both of which take a lot of effort. The graphics cannot be upgraded in any way.