I've been using a carbon fiber Manfrotto mono-pod for about two years and love it. Combine it with IS and you can "hand-hold" down to like 1/10-second. My camera has very low noise up to ISO 6400, so the combination of IS, the m-pod and high ISO really opens up a huge range of possibilities in evening and morning light or indoors.
I use the m-pod for scenics and telephoto, up to my 400 mm limit. Once again, the extra degree of steadyness brings my fhi-def, full frame picture quality up a knotch or two. When I blow them up on the 1080p Sony they look great even very close to the screen.
It's not as steady as my tripod, BUT it's way more convenient to carry and it'll fit in my roller bag for trips. I only use the tripod for long exposures, some macro and making Ebay photographs.