Las Vegas has a great selection of transportation options that vary quite a bit in terms of cost. Many folks take taxis around, but it's not clear to me that they save any time over the cheaper alternatives since during big events you may have to wait in a taxi line at the hotel. The Monorail is fantastic, and it is what you want to take if you are near a monorail station - basically places between the Sahara on North Las Vegas Strip and MGM to the South. This is *the way* to get up and down the strip unless you *really* love to walk. The strip his huge so wear great shoes in any case, even if you'll be taking transportation you'll be walking a lot.
Here is a good roundup of McCarran Airport to Strip and Downtown via bus:
http://answers.yahoo.com/question/index?qid=20070901202908AAGJftl
The $5 shuttles from the Airport are comfortable but usually pretty slow as they stop at many hotels.