I fly overseas alot with my recording gear in carry on. You don't have anything to worry about regarding hard drives, SD cards and that.
Terry suggested mailing stuff. I'd NEVER EVER do that if I had a choice. First, if it has value, it's might get stolen and I've never made an insurance claim even if I had an item insured, but good luck if you do. Europe is generally safe from felons, but it's notorious for light fingered thieves.
Also, mailing overseas takes FOR----EEEEVER. Third, if it has any size, it costs a minor mint.
One major consideration is to ALWAYS carry on your gear. Never check it. It will get ripped off. Airports supposedly have security to prevent baggage from being ripped off, but it's happened to me twice in the last year. Believe it or not, I was treated like the theif when I callled to let them know that my bag had a digital camera stolen...never recovered the cost because I didn't realize that the camera was gone until after 24 hours and the airline wouldn't honor a claim after 24 hours had passed...assholes. They employ f***ing theives and I can't get my stuff replaced simply because I didn't realize that my bag had been hit until 2 days later. The second time I had some meds lifted from my bag, so I didn't bother reporting that. Seriously, they gave ME shit.