let me just say that i submitted amcas on june 19th and knocked out secondaries as quickly as i could get the money. first one came july 17th. i second paean's deadline comments, it's pretty much been the same for this app cycle, just be careful of deadlines as they come in. right now, i know i'm going to med school next year and i'm so glad that, basically, this process is almost done for me. you can submit on july 1st, or anytime until the deadline, but getting things in early is a definite advantage in this whole process.
for sierrasid, i'd say absolutely go! it'll probably be awhile before you get the chance to go to europe again. just be ready to hit the 2aries hard when you get back home. also, a lot of the questions on the apps are similar, so, even before you go on your trip, start cranking out answers to some questions. you can view a bunch of secondaries on my website, see link below. then you can just start sending out as soon as you get home.
good luck to you. i hope you have a great trip. do you know where you want to go overseas?