Check out the traditional multi-sport helmets by Nutcase, Bern and some Bells. They seem more popular among younger folks than the minimal skeletonized roadie bike helmet. I thought about getting one for the winter but it never got cold enough so I'll probably stick with the cooler (as in temperature, not hipness) roadie helmet. If I did more trail riding under heavy tree cover I'd probably consider a fuller-coverage type helmet, mostly to minimize stuff for branches to latch onto.