You should be able to get a fake lip ring at anyplace that does piercings such as a Tattoo Parlor, Hot Topic, Spencers, etc. You could also try a costume shop or anyplace that sells costume jewelry.
If you're looking for clip-on jewelry, you should try looking in stores that specialize in costume jewelry. A great place to find costume jewelry is in a costume or theater store in your area. These stores usually carry a variety of clip-on jewelry.
