If you remember the OPI Muppets collection last holiday season, you'll probably remember the polish called Rainbow Connection. It was definitely the most popular one, seeing as it's a glitter polish. It was pretty hard to get a hold of, so if you missed it, you're in luck.
Here's a couple pictures of the OPI Rainbow Connection polish:
Now here are some pictures of the GAP polish:
As you can see, they're almost exactly the same. If you don't want to go through amazon or ebay and risk getting a knock-off of the real OPI Rainbow Connection, definitely go to GAP and look for their nail polish trios, because that's where I found this polish.