If you could cause one invention from the last hundred years never to have been made at all, which would it be, and why?

Various science people answered this question with embedded advertising, nuclear weapons, calculators (?), landmines, and other weird answers. I thought about this question for a couple of seconds and here are my ideas:

Television. TV can be argued to be the source of obesity, stupidity (jackass, Punk’d), violence, and the retardness of society. Just think how normal we would be without Jerry Springer, if we didn’t have Star TV/Entertainment Weekly/Inside Edition to sate our celebrity lust, or the lunacy of American Idol. Parents would be forced to pay attention to their kids, and kids would have to read books or go out doors. TV is a sinkhole for time with little value, especially if you are watching 24. What do you get out of 24? a story?

Instant Messaging. I am of the opinion that IM is useless. It is a quick and easy form of email. But why don’t we just use email instead? I always have my email client and IM open. I have my friends as contacts on my IM and I have my friends in my address book. Now they both use an email address as an unique identifier! Why don’t we just use email for both? At least sending and receiving is a standard, unlike IMs where there is ICQ, MSN, AIM, Jabber, gTalk, YIM, + countless others.

So what about you? what one invention from the last hundred years would you make disappear?