This is genius!

Then one of my colleagues told me about the trick he uses: When he walks into a room alone, he looks for pairs of people who are talking, and introduces himself to each person. I had always thought I was supposed to approach people who were by themselves. So I asked him: "If two people are talking already, why would I interrupt them?"P

"Because everyone else is there to meet other people, too," he explained. He went on to explain that if you see a pair of people talking, the chances are that they arrived together and know they should be mingling. Or else they've just met and are, in the back of their minds, worried that they're going to end up talking to this one person all night. (You've just made it easier for one of them to exit.) Either way, they're relieved to see you. And your chances of having a decent conversation are better, because now you're talking to two people, not just one.

That is a really good idea. Thank you Christina!