Pearl dust, luster dust, pearl airbrush paint 
I've used Wilton's luster dust before, and also Americolor's pearl airbrush paint, but I don't have an airbrush so I just painted it on with a paintbrush. The luster dust is easier to use and if you brush it on dry, will make a sparkly, slightly glittery look.
You can buy some luster dust and just brush it onto the fondant after you have applied it. Just make sure that the fondant is completely dry, i.e. no patches of crisco from rolling out or condensation. Luster dust comes in a lot of different colors and you can get them either online or hobby shops may carry them. HTH!
Yes, just dust it on with a big soft brush (maybe a blush brush that's never been used for makeup). Kind of pull on the brush bristles a bit before you use it, so that any that will want to come off will come off then and not on the cake.
Texas_Rose: when dry dusting pearl dust on fondant using a large blush brush just like you described, I get sometimes areas on the fondant where the dust will not adhere and it looks blotchy. Do you know what could be causing that? I use Michelle Foster's fondant recipe and roll it on my counter using cornstarch.
Quote by @%username% on %date%
%body%