The Fremont Street Experience is simply awesome. We went to Vegas just for this, as our Dad wanted to see it. I had no idea what it was, but he had E-Mailed me a link and it looked quite interesting. Needless to say, it rocked! If you are meeting friends or family in Las Vegas anyway, oh yeah, definitely do go check this out. A technological marvel. You will find yourself smiling.
So many cheap drinks in the area too. And if you have a hotel in the area, you can just walk around getting absolutely jack-hammered. And apparently people have figured that out long before I came up with the suggestion. :)