Here's a mystery from Brandon over at Welcome to Blog:

I was wondering if you and your readers might be able to help me solve a mystery. When I got home from work tonight, I found a cooler sitting in my front yard. Written on the top of it: ""M.B.I. METRO Q.C. DO NOT DISTURB." Of course, I opened it. Sitting inside were six metal tubes in murky water.

I live over by Lewis and Clark and there's a McMansion being built
across the street from my place. I can only assume the construction
site has something to do with the cooler. A Google search didn't turn
up anything worthwhile.

Photos and further info are up on my blog. Here's a direct link:

http://laurabush.info/2007/05/plutonium-in-my-bushes.html

Anyone got any ideas? If so, please leave a comment over there.

UPDATE, 6/1, 9:40 a.m.: As usual, the blogosphere has the answer.