Yeah,

Don't ask me why clients always stand on stage when they want to see a run through of content. It's a pain in the ass to run back and forth to FOH just to get go and then run back to appease the client.

iPhone is a great deal easier than a second Mac Pro running ARD.

Of course you can also try using one of the VNC applications for iPhone. I have one of these so I don't have to get out of bed and walk to my office when my computer beeps at me in the middle of the night. Of course there are better uses I'm sure.