A white elephant gift exchange is probably the only situation in which re-gifting is appropriate and/or encouraged. I'm involved in at least two of them this year; today I actually went and spent $ buying a new one because it didn't occur to me that I could find something relatively nice, if useless to me, gift lying around my apartment.
For tomorrow's exchange at work, I'm giving away a set of sushi plate + soy sauce saucer that I inherited from someone; it's actually quite cute but I don't eat sushi at home at all, so I've barely even taken it out of its original box.
In the spirit of re-gifting I recycled some old wrapping paper as well as some green tissue that I cut into rectangles and fashioned into little flower-pom-poms. They hide the wrinkles in the paper nicely, I think, and anyway I don't feel too badly about using wrinkled paper for something that will be torn into anyway. Adds a bit to the rustic charm, methinks ;)