flying into one city and out of another in europe

search on various travel sites like www.kayak.com

When you do your search click the button that says "Multi-City."

A couple of approaches. Do any open jaw ticket into one and home from the other. And arrange local transportation between both locations - probably train to Amsterdam or fly to Rome. Or book a three leg trip. Only way to know cheapest is play around with the various travel sites and try different combinations. There is no magic solutions or tricks.

I spent a little bit of time playing around with different options of multi-city vs. single city + train to go back (and I played with different dates, such as weekend vs. mid-week) in a spreadsheet. I found that Icelandair had really good open-jaw (multi-city) rates and went with them. I think my order of cheapest was Iceland then Continental (through Houston), then British Air. You might find BA the cheapest if London is your first city. I am flying in to Paris and out-of Frankfurt for the same price that either of them would have been round-trip with Icelandair (I promise I am not a spammer, and I can't vouch for their customer service or anything else, yet, although my parents flew with them and were happy with the experience.)

also, play around as a guest on itasoftware.com...though you can't book through the site, I find it shows more options than traditional travel-booking sites.

KLM is having a sale now, ends in a couple of days. You might get a deal there, if you opt for Amsterdam.

i always do this when traveling in europe. don't think i have ever returned home from same city i arrived in. as others mentioned - plenty of websites to assist. i always use sidestep.com to find ticket from US to Europe. select multi-city function. then i look for (budget) intra-europe tickets on whichbudget.com. these two sites have served me well and made planning travel very easy and affordable.

Curtis - What time of year are you think of flying?

I use kayak.com to get a rough idea of flights, then go to the specific airlines website to check for deals.

You may also want to subscribe for a site like airfarewatchdog.com to help keep an eye on fares for you.