doggie, how far you can go depends on the rest of your gear.
is it an oem like dell/hp? all oem's lock their fsb so you cant pump it that way, some of the intel 815s can depending on a few things.....
if its a white box that someone built for you.. it depends. memory, psu, mobo all come into play. you might be able to get a small o/c outta it.
xperties, the only intel chips i have "seen" that are multi unlocked are r&d pieces, and those only go to very very special people. in other words, not us.