Granted, I would need to pay for in-country city-to-city transportation in a couple of places, i.e. from Paris to Normandy or Rome to Naples, but those are day-trip distances, so the fares wouldn't be astronomical. The Eurail pass (for 3 countries) costs $275 for six travel days or $325 for eight travel days, so the actual difference in cost - after adding the airline taxes - will probably work out to be negligible, but the difference for me lies in the ease and speed of travel. I would much rather just fly all the way from Paris to Rome, for example, than take the 12-hour overnight train - especially for 15 measly dollars, which is what the flight costs. Also, this would indirectly save me money in the form of daily costs like food, etc., because the trip will take less total time. Decreasing the travel time will also do a lot to preserve my sanity. I like trains, but there's a line, and I think three solid weeks of trains would cross it. Besides, you can't travel for free on any train you feel like, even with the Eurail pass; you still have to pay supplements on any of the 'good' trains like the Eurostar, ICE or Thalys.
So, I'm leaning towards flying. That was really the point of this entry. The only problem I have now is figuring out what order to do the countries (France, Italy, and Greece) in so that I (a) get the cheapest possible rate from the States to Europe, (b) can get back out of Athens (with its appalling lack of out-of-country flight destinations) without having to go back to a country I've already been to, and (c) can stop off in the Netherlands for a few days either before or after the trip (or both :)).
Oh yeah, and getting my answer from the camp, and figuring out what in the world Christine is going to do, since she still hasn't answered my e-mail.
(...And resolving the nuclear crisis, and obtaining world peace... sigh.)