I've got a black and gray one from Combat Flip Flops. It's soft and light and folds up pretty small. It's awesome. Also use it for a blanket and pillow in the tent more than anything else. Every now and then i think about buying another one because it's my most luxurious item of clothing, but i agree that it probably is more weight and space than it's worth to carry a spare.
I find myself using a normal bandana more often for tying hair out of my face because it's quicker to tie and leaves my neck free. Also works better under a bike helmet. I do wear the shemagh desert style when i am in places where sand will blow in my face, tho, or occasionally when i am out of sun block and want a bit of extra coverage. It's also a comforting way to get that hoodie feeling when you are on the road, because actual hoodies are way bulkier and much less practical to haul around.