These are awesome:

[VIDEO]] Tifosi Dolomite 2.0 1020304831 Wrap Sunglasses,Black & White,141 mm: Clothing[/VIDEO]

You'll never win any fashion awards with them, but I've used them both on the road and on the trail cycling, and I wear them running. They're vented enough so that they don't fog up, but keep the wind out of your eyes. They're also photochromic (they get dark when it's sunny out) so they're great for day or night activities.

Good stuff.