Alex is the Bicycle Tutor. He's a bike mechanic in Vancouver, BC, and he posts bike repair and maintenance video tutorials to his blog. Very helpful stuff! Go see the Bicycle Tutor for bike care tips and instruction.
Which reminds me: I need to change the chain on my road bike. I have 1500 miles on my current chain (10 speed) and it's already stretched. At $50 a pop, those 10 speed chains are not cheap.