And use lots of agitated hand gestures and arm-waving.

'Course, we're likely to find ourselves in the role of the locals watching the alien equivalent of Ugly Americans swaggering around and expecting us to learn their language. Contact between societies at different levels of development is never kind to the laggard.

Figuring out what to say is an interesting challenge. I fall somewhere between the extremes of faith that advanced aliens would be so enlightened that we'd have nothing to fear, and xenophic terror. "Trust but verify" would be smart. The first item on the agenda is determining their intentions, and perhaps offering to trade would be a good tactic, since what they'd be interested in would reveal a lot about their interests. As would their questions--it pays to listen. I'd be very worried if all they were interested in was technology with military applications and their questions seemed to probe our strengths and weaknesses.

Of course, there's more than one way to be conquered. Read General Petraeus's "Counterinsurgency" manual some time. A lot of it is a handbook on how to "seduce" a civilian population, the quest for their "hearts and minds" put on a businesslike footing. The friendliest aliens might be the most dangerous.

Xenophobia would be a handicap, but a little paranoia wouldn't hurt.