This is a style question.
My wife and the co-founder of Xero Shoes, Lena Phoenix, had really mixed feelings when we came out last year with our Z-Trek sandal and this year with our Z-Trail sandal, because they're sport-sandal you can easily wear socks. ;-)
If it's cold you can just wear a good pair of wool socks sport sandals. If it's warm, you can wear a synthetic that has wicking properties and is valuable in other ways.
So, yes, can definitely wear socks with sandals, although people might look at you a little strangely, depending on what you wear.
Personally, I have a collection of tie-dye socks that once I started going barefoot and wearing huarache-style sandals I almost never wore. But with the sport-sandal style, I pull them out every now and then and they look pretty fine.