CoverGirl Flipstick for free as a part of BzzAgent. I received three different colors (Perky, Minx, and Stunner. The last of which I gave to my coral loving mother in law).
Each tube comes with a color on each end, one matte-ish and one with a pearl-iscent shimmer. It's awfully convenient, having to only flip the wand back and forth to mix colors. Although I found the shimmery color too shimmery for my taste. The best look I found with them was to apply the matte color on the whole of the lips and then the shimmer shade on the cupid's bow and very center of the bottom lip (it makes them look a bit more plump). The quality is what you would expect from Covergirl: decently intense color, smooth application, although not overly long lasting. And the taste (because let's be honest, we all end up eating our lip color accidentally) isn't offensive.
The verdict? Not a do over for me as I prefer an uber matte look for lips (on tap for Spring 2013 trends), but if you like playing with colors try them out. They'd also be perfect for travel or schlepping back and forth in your bag to save space.
Have you tried the flipstick?