For the future you should use a can of compressed air, they sell them at most computer stores. It uses a powerful jet of benign air to throw the dust off the board and onto other surfaces (usually the desk) where it can be safely wiped off. It's usually best not to touch the electronics with anything if it can be avoided.
I suppose there might exist some kind of non-static cloths out there, but even if static isn't a worry the PCB is usually full of little pointy bits that will just catch all the fibers... using a cloth doesn't seem like the best idea to me