My dad was an engineer who managed teams and fixed auto-pilot systems in airplanes, so we would travel often and stay in different countries for prolonged periods of time.
I lived in Atlanta for three years when I was very young and picked up a southern accent while I was there. Afterwards, we moved to England and Scotland for a few months. It didn't change my southern accent, but I did learn how to mimic a British accent, much to everyone's amusement.
There were short trips to other countries like Germany, France, and multiple times, Japan, but I never developed any accents from those.
Now that I've been back in Thailand for about ten years or so, I'm getting this weird Thai accent mixed up with all my other accents. I don't even know what accent I have anymore.