[KarmaKiller]

^ That probably has a better VID then what Burts chip has.

@Burt
3Ghz may not be your max. Every chip is different, no matter how similar they are. (if that makes sense)
My first suggestion would be to upgrade cooling. You can get a better clock, but your temps are gonna cause all kinds of stability problems more then likely. So I would look into some better cooling first, then you'll have some more headroom for OCing.
I notice you have a P35 mobo. They are still good solid mobo's, but there are better clockers out now. I really don't think you need a upgrade, or at least IMO. But you could step up to a P45 chipset, maybe even a 780i. Both are proven to OC Quads extremely well.
But then a whole other side to this, is the new Intel i7 is out now. And really, if your wanting a nice jump in performance, that is really the way to go. But that also depends on your budget too.