I second this. Monoprice is great. Their cables are dirt cheap yet at least as high quality as what you'll get anywhere else. They're also great for adapters.

I second this. Monoprice is great. Their cables are dirt cheap yet at least as high quality as what you'll get anywhere else. They're also great for adapters. I bet 10% of the people reading this have paid Apple $30 for a Mini DisplayPort to {VGA|DVI|HDMI} adapter. I got all 3 for $30-something.