Yes, but you still need to register with the AMA.
It was a little confusing - especially with the AMA guys not knowing exactly what to do either.
I'm from Germany, registered with the DMFV and have insurance all over the world, even outside of designated model aircraft strips. But they still wanted to sell me a full blown membership... which I found kind of stupid for being in the US for a few days.
I asked around and people told me that there should be a membership for international visitors, but the AMA person I asked didn't know...
So I just enjoyed the stay, had fun with people from all over the world and didn't fly once (well, once with Josh, buddyboxing a Bixler =))