Well, now comes along the Megabus. A double-decker bus that will get you to Las Vegas for as little as $1. Starting December 12, 2012 you can jump on a bus all the way to the Las Vegas strip. The bus comes with free wi-fi and until December 19, 2012 the cost is $1. After the December 19 the cost of the trip goes up the closer you get to the departure date but they still start at $1. I just did a quick search using Expedia.com and a flight for December 20 - 24 LAX to LAS was priced at $145.60 and the same trip with a ride on a Megabus was $6.
If you consider a road trip to Las Vegas you would spend more money on gas alone and then you factor in parking and tips for the valet. While I'm not sold on the idea until I actually hop on the bus and experience it, I'll be the first to tell you that if it is as good as it sounds can you imagine how that changes your vacation plans? You can take a side trip to Los Angeles from Las Vegas. My friend and fellow About.com Guide to Los Angeles, Kayte Deioma, will find you plenty of spots to spend all the money you have saved on transportation.
I'll be on that bus soon and I'll tell you all about it.