The CAT Bus offers a 24-hour pass for $5, a 30-day pass for $30, and individual rides are $1.25/way ($2.00/way on the Strip). Even at $1.25 a pop, the bus is still a lot cheaper than a rental car or cab. Also, remember, there're several free shuttles connecting major Strip and off-Strip properties, like the Barbary/Gold Coast and Harrah's/Rio shuttles.
How is Big Elvis doing and where is he performing now?