Just last week overlclockers had managed to tweak the Phenom X4 955 processor to more than double stock speeds, after only being available about a week. Now that they have had some time to play with it and really get to know it, they've blown the 7GHz barrier away.
Chinese team LimitTeam managed to take the Phenom II X4 955 processor up to an impressive 7127MHz. They used LN2 to cool the proc while raising the voltage all the way up to 1.95V.
Another overclocker has supposedly manage to hit 7.2GHz, however his multiplier seems impossible to hit and thus many aren't considering it official.