Cabs are plentiful and expensive. The city bus system is straight-forward and easy to maneuver if travelling mainly on the strip. It also gives you a chance to meet locals, and get information from folks who live there.
Cab if outside the strip, bus or on foot while up and down the strip. BRING COMFORTABLE SHOES!!!
A car is very useful! But you can walk the strip although this can take time as it is about 4 miles long!...Taxis and Limos go up and down the strip and there are also buses!
Picture : The Big Shot on the Stratosphere