021: The high cost of HDMI.
There are several ways to hook up your DVD player or cable box to your television. The latest and greatest connectivity method is known as HDMI. A single HDMI cable can carry all of a device's high def video and audio output to a digital TV in pure digital form -- the signal isn't converted to analog until it hits the display screen and speakers.
So HDMI is clean and efficient. Is there a catch? Oh, yeah. That'd be the retail price. Best Buy's "bargain" HDMI cable costs 50 bucks, and the cheapest HDMI cable I've seen at Wal-Mart is almost 30 bucks. Which wouldn't be an issue if you couldn't find them online for less than five dollars.
If you're in a hurry for an HDMI cable (as I was recently) and can't wait for shipping, check your local Apple Store. They carry an "XtremeMac" branded cable for $19.95. I wonder... is this is the first time Apple has undersold Wal-Mart on anything? Maybe they're hoping their HDMI deal will help them move more Apple TVs.
EDIT: Arik Sokol mentioned in the comments that he saw HDMI cables at Big Lots for $11.99. Thanks, Mr. Sokol!