Here's an inexpensive and lightweight way to add movement with your camera at different heights. YouTube member ImagineNowEntertnmnt used furniture sliders from his local Bed Bath & Beyond (as seen here) and placed it under each tripod leg [Thanks Justin]. The furniture sliders can glide along carpet, linoleum, ceramic tile, and cement, etc. With a mini tripod, I can see this being a handy tip for Wedding Videographers who need to travel light, but have access to lots of smooth surfaces to add slow camera movements.
There's a bit of shake in some examples which could possibly be corrected with a bit more weight hung on the tripod, or some post image stabilization, but in most cases it works quite well to add interesting camera movements to your footage. Pretty common stuff you can find at your local Bed Bath & Beyond, local hardware store, or even find available via Amazon (click here)
Reusable Furniture Slider Kits