You can run any cpu you want to, just not as fast as you might like. Everything depends on how fast your front side bus can go, and weather you can change your multipliers.
Amd has started to lock the multipliers on their chips now, so if the 133 in the name of the board implies that you can only do a 133 fsb, you are best to get a procesor ment for a 133 fsb.
I think that the mobile XP's use a 133 fsb, and they have unlocked multipliers, so getting one of these is probably your best option.
If you were to get a 2500+Mobile, you could run it at a 133 or higher fsb, with the multiplier of your choise if your board can change the multipliers, and then if you ever get a new motherboard, you can lower the multiplier and keep using the same chip.