Those things that you have to type in the box when you want to do anything online.
Why, when I purchase concert tickets, post blog comments, buy something on eBay, or anything ever, do I have to type crazy words and codes? I got it when it was a verification that I wasn't a robot, and I had to type "c37ds" (are you sure you're not a robot? are you SURE?), but it was sort of hard to make out because it was in a crazy font or curved or something...but today, in order to sign up for the FREE Hilton Dining Points program (which is awesome), I had to type "rosencrans ethereal." Really? Also, if some robot wants to sign me up to get free points, do it. Don't make it jump through hoops!
And let's not lie...no robot out there is buying me stuff on my eBay account...and honestly, if it was, I'm sort of interested in what it would buy for me.