The one we've got is running 1Gb of Kingston HyperX 1066GHz. Eg. At LambdaTek. You might find it with delivery included elsewhere, eg: CCL Depending what you buy the delivered price per GB varies.
That's with XP Pro on it. With Vista you'd need at least twice that for the same performance. Seriously if you are using Vista then throw as much memory as you can afford (up to 3 or 4 GB anyway). Win7 is rumoured to be more capable of accepting less memory.
Note: With this motherboard you can install a matched pair of Memory DIMMS (same brand/speed/etc) and it will run the memory in dual-channel mode giving you extra speed.