Here's something interesting that washed up on an island along the flight path:

http://www.maldivesfinest.com/mh370-evidence

I would have to imagine that stuff is all serial numbered and they would be able to figure out where it came from rather quickly.

I thought I've heard of those coming out of space craft and satellites on a regular basis too and that it wasn't that unusual to find them washed up on beaches. However, that thing would be pushed by the wind as easily as just about any debris out of that thing...so who knows?