Ornamental sweet potato vine (Ipomoea batatas) is a great addition to container gardens. It typically has either impressive lime-green, heart shaped leaves or dark wine, cut-leaf foliage (there are new varieties too). I haven't tried this, but I read that the tubers can be lifted from the pots to overwinter for next year. Pull them gently out of the pot & store tubers during winter. In the spring, you're supposed to be able to plant the tubers with your annuals and have them re-sprout.