I can get mine up to 2.85GHz, but to do it I have to keep my memory ar 266, so at 2.85GHz my memory runs at 346MHz, and I do not get a performance gain over my normal setting of 2.75Ghz with 415MHz memory. My memory will not go any higher than 415 without a crash, which sucks becuase I bought non value memory just to be able to overclock and it turns it has no headroom. oh well. I guess 2.75GHz is enough.
EDIT: 2.75GHz is on stock voltage too.