Two Different Departure Cities

Not sure I understand the problem. You can run travelocity or kayak or whatever multiple times at the same time in different windows. No reason you have to book both tickets on the same transaction.

Yes you can do that, but there are so many options. I want a service that does all the iterations/permutations for you and presents you with the best options. Otherwise, you are wading through hundreds to optimize/minimize travel time, number of stops, and cost. It is quite an ineffective process.

Just an idea, can you both pick a city, say Chicago or whatever and both get there a day early so you can get on same flight to Europe and go home the reverse?

It's a classic time vs. money trade off. I just booked my plane tickets for a fall trip to Europe, and sorting through all the permutations for just one person took a great deal of time, especially as I wouldn't accept a connection under two hours - and a LOT of shorter ones showed up. I was also willing to fly out and back from any one of several cities, so that increased the options.... If you don't care so much about the price, or are willing to pay a travel agent then you'll opt for the money side of the trade off. Good luck.

You can't do this in one booking. But it is not that difficult to do it manually. It would help to make the search with two windows open so that you can search both itineraries at once, when you have narrowed your choices down, you could play with the advanced options (search only specific carrier, only within certain time frame etc.) to force both itineraries onto the same transatlantic flight.

What you are asking is so narrow that probably would not be dozen people a year that would need that option. However, I think it would be easy to do by yourself. I would work backwards. The big hubs like Chicago, New York, Dallas, etc. generally will have the best flights and options. Work those hubs to see who has the best direct flights to Europe. Once you have decided on that use the multi city option to schedule a four leg flight -- your home to hub, hub to Europe, Europe to hub, and hub to home. You and your friend need to decide that you will be leaving Chicago at 8 pm on a Thursday night and each is responsible for getting there in time. I am guessing I could do all of that in about 30 minutes. And travel agent doesn't have access to secret program either.

Separating the flights will make the trip more expensive. Get a travel agent, or spend time searching. I personally enjoy the challenge of searching for best flights overseas. Yes, it takes a lot of time. Start with two meet up cities, Chicago and Newark would be my choices and run some samples from those two. I'd set up some daily alerts on Kayak to get an idea of what prices are going to be. I'd also work with non-stops from your US city to your destination in Europe. You don't say where you're going in Europe. LHR is always cheapest. AMS used to be cheap, but I'm not finding that it true anymore.
Enjoy!

Just do them separately...No biggie. That's how an agent will do it. Where is your partner leaving from? Is it somewhere where you can meet him/her (large city), then continue? Otherwise, search for airfares and routes separately, then pick the city that is a common denominator in your searches. When you put in the info for your search, the airline site should show you every possible combination for your criteria...Do this for both people, then pick out the city/cities that are in both and go from there (choose according to price, times, etc.). Unless you want a bunch of connections, there are only going to be so many choices...The big gateway cities in the USA are (direct or not) places like Seattle, San Francisco, Los Angeles, Dallas/Ft Worth, Chicago, Miami, New York, Boston...After 15-20 minutes of playing around, you'll start seeing the pattern you're looking for - which cities are possible meet-up cities.

What you can do is search some of the cities that you are interested in visiting from both of your hometowns on kayak and then go to the "Airports" section and see what the choices for layover city is and unselect all of the options that do not show up in both of yours and see if that helps. I have a similar issue that I am in nyc and my boyfriend in LA and we look for places to meet that are about the same price as one of us crossing the entire country bc that trip gets tiring to do for a 2 day visit. Found your post while search for a site that would help us narrow down the cheapest rendevous city would be for the two if us.

Rachel, Which city is your travel partner flying from? The easiest solution in this case would probably be to enlist the services of a Travel Agent. They could likely set-up an arrangement with code share flights, so that your baggage won't need to be re-checked during the journey. As Frank suggested, it would be a good idea to choose a major hub airport to meet your travel partner, such as ORD or JFK. Those will offer a greater selection of flights to Europe (hopefully at good prices). If you want to work out the details yourself, it is possible but will require some work. You might try using This Website, using the "Multi-City" search option. I tried an "experiment" using ORD as the meeting point, CDG as the destination and FCO as the departure point for the trip home. The site presented a number of options, but unfortunately the cheapest fare was $1745 (total). With this search method, I wasn't able to tell whether the flights would be "code share" or whether you'd have to deal with your baggage during the trip. The method I use for international flights is to research what I want on the net, and then have a Travel Agent take care of the booking. She often suggests better alternatives or ways to streamline the trip, and often gets me a better price than what I've found. Good luck and happy travels!

If you book your tickets separately, you can call the airline as ask them to connect your two reservations where you are on the same flights. So in the event flights are cancelled or changed, you two will remain together with the same itinerary (in theory). I've done this several times with United where I've combined a business trip with a vacation. My husband and I have separate itineraries to Europe, but our reservations coming home are "connected".

What you might want to do is pick a couple of big US cities, NYC, DC, Chicago.... figure out the cheapest flight that works for you from each city. Then figure out how much it will cost to get to those three cities to catch that flight.

When you search on kayak.com, one of the options on the filters along the left is "show layover airports." I would search both routes separately and see which layover airports are common between the two. You should be able to narrow down to flights that put you on the same second leg.