This will keep you busy for awhile:
http://www.vegas.com/
http://www.lasvegas.com/
http://www.lvol.com/
This is the monorail, it has expanded since I was last there and they do charge. Note that it runs behind the casinos so it may be a short walk, don't know if any of the casinos have stops in, near, or connected to their building, click on route map.
http://www.lvmonorail.com/
Then again if you want to go first class every resort has a row of taxis lined up in front.
Are you night people? Going outside at night isn't too bad. What is your idea of a long walk? The old casinos are close to each other but the new mega resorts it can be a hundred yards to the strip and a half mile between establishments, then because of the giant scale of everything it looks like it's not that far away but a stroll to the next casino can turn into a hike.