Chunk of the Blarney Stone
Unlike the parent Blarney Stone, which requires a contortionist's twist to kiss it (not to mention a trip all the way to Ireland), this tiny chunk is conveniently cemented onto the top of a small pedestal on the campus of Texas Tech University.
Its origins are mysterious. According to a plaque on its pedestal, the stone "was uncovered by a group of engineers near here on March 7, 1939" and "was found to be identical with a piece of the original Blarney Stone which disappeared in from Blarney Castle near Dublin, Ireland in 1659." Perhaps the obscurity of this chunk, or its small size, has kept Ireland from asking for it back.
The Texas Tech Engineering Society has decreed that no Texas Tech underclass engineers can kiss the Stone, although that doesn't forbid any tourist from taking a smooch. But you may want to bring some sanitizer. It's a tiny chunk, and every square inch has probably been pressed by a lot of lips.