6 apps for saying something when you have nothing to say

Tweeting, texting, and other forms of messaging have rapidly taken over our communications, but sometimes even 140 characters is too much. A slew of new apps are pushing to slim conversations down to little more than an acknowledgement or quick drawing. This race started with the introduction of Yo in April, and it doesn't seem to be slowing down -- actor Aaron Paul and AOL (the owner of this site) just dropped new apps this week. So which ones should you choose? (Or not choose -- just give your family/friends/pizza guy a call already, they miss you.) We have a few candidates lined up.