I have been in my house for about 13 years and I've always wished I had a door to the laundry room in the basement. I have a TV downstairs and my sewing area, so it was noisy when the washer was running and I wanted to use the family room. The door to the laundry was framed out without a door--and a traditional swinging door would take up precious space in the narrow room (or make it really hard to move the washer out should I ever need to replace it).
I decided to give the barn door trend a go. I went to Habitat for Humanity's ReStore and picked up a hollow core sliding closet door and painted it with chalkboard paint (with white trim). It was a steal since the door was only $5 and I had the paint left over from other projects. I had to build my own track because my ceiling is only 7 feet and all the hardware I could find needed a bit more headroom than I had.
Next, I added a wooden header across the whole opening and screwed it into the studs (which are not 16" on center...darn old houses). Then I undid my work because I realized that the trim around the door stood out further than my bracket. I put in spacers and hung the wood back up.
My friend made me some J track with holes for screws, which I screwed into the wood header.
To hang the door, I used closet door hardware as well as a couple of casters on the bottom of the door. The hanging closet hardware keeps the door on the track; the casters hold all the door's weight. It rolls across the carpet fairly easily--if I were doing it again, I'd probably use larger casters.