Yes! Finally a list of free stuff to do in Vegas. Many of these attractions are great for those those mandatory Facebook pics. Personally, I think this list is better served as top 10 FREE date ideas for Vegas.

1. Bellagio Light and Water Fountain Show This is probably the most recognizable monument in Vegas. Plus you and your buddies can get someone to take that famous Ocean 11 shot of your crew – of you guys just staring into the fountain. Just make sure when you get the picture, you don’t let that tourist run away with your brand new SLR. The great thing about the water show is that every couple of weeks, they change the song and the fountain setup.
2. Wildlife Habitat at the Flamingo Hotel and Casino When you are too cheap to go to real zoo, Vegas hotel lobbys fit the bill. They got tons of pink flamingos and other animals that would never have survived it in the outdoors of Vegas, so of course they too need 4 star accomadations.
3. Conservatory and Botanical Gardens at the Bellagio Hotel and Casino One of the prettiest photo spots in Vegas. It has a spectacular floral display, which would make any girl swoon. There is a 50 foot glass roof that gives great lighting for pics. Plus, each season the designer changes the displays - so there is alwasys something enw to check out. Overall, great place for those macro shots of plants and an even better place to meet girls. Just stand there and I guarantee you , girls will be asking for your help to take a picture of them. To make this really work, make sure you stay with the D.E.N.N.I.S system from "its always sunny in Philadelphia" lol. So get out there and complete the first step - Demonstrate Value (ie. take thier pic - plus, make it a good one / use a wierd angle).
4. The Volcano at the Mirage Hotel and Casino This is the hotest place in Vegas - literally! Seriously, its Vegas - why would anyone want to make it any hotter?! But the crazy developers at Mirage made this spewing hot lava mountain in the middle of the strip... Yup only in Vegas..
5. Fremont Street Experience The real attraction here is the ceiling. It's loaded with crazy lights and graphics. Seriously, this is probably the best place to go after a rave.. Know what I mean! Holla.
6. Sirens of TI at Treasure Island Hotel and Casino Who doesn't like half naked girls - dancing, fighting with swords, acrobatics, fire and pirate ship. It's totally cheesy like the movie - but it's all good, I enjoy it. Its every night.
7. Rock and Roll Memorabelia at The Hard Rock Hotel and Casino The Hard Rock Hotel and Casino has a great musuem of memorabelia from your favorite artists such as; Beatles band gear, Madonna's underwear, chopppers from Guns N Roses' Matt Sorum and guitars from Motley Crue, and hundreds of other signed band equipment.
8. Masquerade Village Show in the Sky at the Rio Hotel and Casino Yup, its like New Orleans without the nudity. But its a positive cause seriously who wants to see a 60 year  old lady flash her goodies for a 10 cent necklace. Gamble right at the slots and the necklaces will be raining directly over ya. Cool stuff.  
9. Lion Habitat at the MGM Grand Hotel and Casino See lions chilling, mating, fighting but never pooping. I don't understand it either - I stood there for an hour or two waiting for one of them to poo or even just a tinkle.. Not  even once! Something must be up with these animals, maybe they are on a strict diet of some crazy protein shake or something.  
10. Circus Acts at Circus Circus Hotel and Casino One of my best memories growing up with going to the free circus at Circus Circus. The show has aerialists, jugglers, trapeze artists and clowns. I know, you are probably scared of clowns too - everyone is. Go to the big top which is one floor above the casino. The show last about 10 minutes.