I really like the Art-o-mat machines at the Cosmopolitan.  I wrote a post about the machines a while ago (Art-o-mat Machines at the Cosmopolitan), but here is a bit of info about the machines and how they came about.

http://inhabitat.com/vintage-cigarette-vending-machines-upcycled-to-dispense-art-instead-of-cancer/

(updated June 4, 2015)
Here is another lesser known, but neat thing to check out while in Las Vegas.  The Art-o-mat machines located around the Cosmopolitan.  I have seen two   by the Wicked Spoon buffet on the 2nd floor. one on the 3rd floor by the sitting area at the top of the escalator (not far from the Secret Pizza place), one in the heavily trafficked area on the 2nd floor in front of Stitched and one on the ground level  by the Lucky Cat exhibit.

The Art-o-mat machines are reconditioned cigarette machines that now dispense art and jewelry in cigarette pack sized boxes for $5.  The inventory does rotate and everything appears to be handmade, so it is worth checking out on every trip as far as I am concerned.

Here are a few examples from a recent trip.  On the left is a hanging “mosaic whimsy” piece made by Janie Reavis-Cox from Stigler, Oklahoma.  On the right is a pair of earrings made by Crystal Ladd, who has additional pieces available at deflora.etsy.com.  We also found painted wood blocks, necklaces, and merit badges.

You can’t see the exact item you will get before you put your money in and pull the handle, but you can see a basic description.  Each item is only $5, so give it a shot.  It might just be the best gambling deal in Vegas.

To see a machine in action, check out this YouTube video.
Note that the machine in the video takes tokens and the machine that are at the Cosmopolitan have bill acceptors.