How far in advance of a trip does everyone typically purchase air?

No set answer. A lot depends on when you are planning to travel and what your particular objective, i.e. are you looking to travel on a specific date or are your travel dates flexible? Are you seeking the lowest price? Do you have a preferrence for Class of Service? Are you planning to use FF miles for an Award ticket? Are you planning to go during peak travel time sch as Christmas, school holidays, etc?

If you are seeking FF Award tickets these can be difficult to get and most people book them when they first become available - 330 days out.

If you are seeking the lowest price, the best approach is to first get some idea of what a good fare is from your area. You can then start checking fares on a regular basis. When you see a good fare - book it. Generally speaking you'll find the best fares anywhere from 6 months to 3 months in advance but that's not always the case. Airlines sometimes have fare sales but they may require travel within a certain time period. Often, the closer you get to your planned departure date the higher the price. Same holds true for peak period travel - don't expect bargain fares.

I agree with A_Traveller. I usually purchase my tickets for May in the Fall of the previous year.

You can use a farefinder too, one that will email you when the fare changes. I use Travelocity. Sometimes it works; sometimes is doesn't.

Peace, Greenie

Kristen, I agree with A and Greenie. I just booked a flight from Baltimore to Turks & Caicos on US Air for end of March, there were only 10-12 seats available in coach.

I was just curious to see if more people book in advance or wait til closer to the trip.

We travel in Mar and try to buy before Thanksgiving day as it seems to be the perfect day for all the airlines to jack up the prices. I think they figure that people are together that day and begin making plans.

If I see an outstanding airfare deal, I book it immediately no matter how far in advance of the trip it is. (Assuming that I've chosen dates already and an island)
If I don't see a great fare come up, I usually buy tickets about 4 weeks ahead of time unless I know it's a busy time for the destination (holiday, carnival, special festival, etc) OR if I'm flying into Beef Island in the BVI. For some reason, the three times I've visited the BVI the prices jumped outrageously even a couple of months out from my travel dates, so I will buy those tickets early in the future if my travels take me there again.

What do you do?

I do it a little backwards.

I try and find a couple lodginging options that are available for certain dates. I try and make sure that there is availability on both ends of those dates. Once I have nailed down where to stay and know that the place has availability. I call around to the diffrent airlines, and tell them to find me the cheapest flights to that destination. If you tell the airline the dates are flexible by a few days, you can usually find mid-week departure dates that seem to be cheaper.

I know it's backwards....but it seems to work for me.

I tend to buy in advance if I see a good deal..I am too nervous that the fare will go up!