Sorry it took so long to reply, I had to do a little research first...
Depending on what time of day you arrive in Las Vegas, you can usually find a taxi waiting somewhere close by the airport arrivals area (on the left side of the baggage claims areas, you'll see them when you walk down the stairs).
If you have a few extra dollars to spend, the lemosines are usually lined up on the far left side of airport arrivals.
I think you can walk up to them and pay for them right there, but I'm not sure about that since I haven't done that before.
It will cost $13.26 per person to travel to Aria from the airport via taxi, according to an online search I made.
My wife and I always get a round-trip shuttle ticket to one of the strip hotels, which can be paid for just outside the airport arrivals area.
I've never taken a cab from the airport, but I think you can flag one down.
You could visit one of the rental booths outside of arrivals and ask them first.
I know guys don't like asking for directions, but in my travels I've learned you need to walk up and ask someone to find out how things work in most places you travel to.
I hope this helps you out a bit Dippy Lippy.