This past week, I've gotten two different e-mails from two different friends about the "What If" section at XKCD. Now, most folks are familiar with XKCD for their comic strip, with many examples showing up around the net.
Daniel in Brookline sent in this one about the line from Armageddon about stopping a train with a BB gun, and Andrew sent in the Machine Gun Jetpack one. What XKCD does is similar to Mythbusters and examines the science behind these ideas - plausible or not - and explains why they would - or wouldn't - work based on the hard, cold physics.
If you're a science geek at all, or just like cool stuff, go take a look - it's a great way to lose a couple hours, easy.
That is all.