the only one that i can think of off the top of my head is the ecs k7s5a, not the best board out there but it is pretty darn cheap (it will only take 1GB of ram, cuz it only has two slots of each type of memory that hands 512MB DIMMs, it does support all current athlon xp processors)
i don't think there are any others that are widely availible...
(i could be wrong tho)
Josh