I can match just about any color on earth by mixing/blending paints. I can see something once, remember the color and recreate it nearly perfectly weeks later. If color copiers hadn't been invented I could have had a great job.
I can do the Star Trek hand sign thing (don't know what it's called...not a Trekkie) and alternate it with switching to pinky and index finger out.
I can also do a really good imitation of a squealing pig. (yes, insert comment here.) Most people try to do it with their nose but it's actually a throat thing.
Oh, I can also curl my tongue and flip it over, but only on one side.
All completely useless.