Tiki Ice is a small stand in Town Square Las Vegas, near the central Childrens' Park area. They serve delicious, natural frozen fruit treats that are quite inexpensive, and they strive to be environmentally conscious in their business model.
Apparently a student-run business, all the people who work there are friendly and offer free samples of their wares. With compostable cups and spoons made from plant starches instead of plastics (oil!), and entirely reasonable prices ($2 for a scoop!), I highly recommend it.