Put Them to Work - Most of the time, guests are aware that they're early and that you might not quite be ready. We find that these guests are more than willing to pitch in to finish up the last details. You can ask them to light the candles, open the wine, toss the salad, or some other small task that keeps them occupied while you finish up everything else.
Make Them the Greeter - Ask your early-arriving guest if they might like to open the door for other early arriving guests. They can pour wine, dig in to appetizers, and keep each other entertained for a few minutes.
Let Them Hang Out - If you can cook and talk at the same time, give your early arriving guest a glass of wine and let them hang out with you in the kitchen. Often this quiet one-on-one time is a nice way to begin a party.
Have Them Choose the Music - If you're not particular about the music for the evening, hand them your iPod or point them to your CD collection and let them go at it! You can give them some direction about the kind of mood you'd like to have during the evening or just see what they come up with themselves!
Invite a Designated Early-Arriving Guest - If you're throwing a large party or you have a feeling you might be rushing to finish up, it can be helpful to ask one of your guests to arrive a half hour early to help out with the surprise early-arrivers. For us, this is usually a close friend who won't mind being put to work and one is naturally social.
What are your strategies for guests who arrive early?