The world of Celeron

Ok, now Celeron chips are hitting the Ghz. Theoritically, you can put one of those 1.2 Ghz Celeron processors into a motherboard that currently has a 733, or can you? I was examining my board and it has NO jumpers for the processor. Also, my manual said that the processor sets itself or the bios does. Can I upgrade further or have I hit a dead end?