You know that awkwardness where there's someone in the group that you haven't been introduced to and there doesn't seem to be an opportunity coming up, so you just have to go for it and introduce yourself else you'll just spend the rest of the time hanging out embarrassed and ignoring the person because you don't know their name? (If that doesn't crown me the Queen of Run-ons, I don't know what will!) Anyway, to solve the above-mentioned situation, here's a great line that was actually used on me yesterday.
"Here, I'd better introduce myself before you start calling me names. I'm Rolf Kars."
Isn't that great? I'm so using that line next time that happens to me.