Handling Interruptions

I was recently at a prestigious, high profile networking event. I got in a conversation with a well known CEO but we kept getting interrupted. What are some clever techniques you have used to keep people's attention in situations like this?

Networking events can be like walking a tightrope between courting potential clients and warding off irritating interruptions. It can be incredibly frustrating to get to the point where you are in conversation with a potentially valuable individual and just as you are about to clinch the next step, some arrogant oaf or sultry sophisticate seemingly materializes out of nowhere and proceeds to have a conversation that is designed to immediately eject you into the crowd.

Its important to understand a couple of things here.