Most prominent in the frontman of the Foo Fighters Dave Grohl (and thusly named after him), the Dave Grohl Effect is when a man looks far, far better when he has a beard. Examples of more people the Dave Grohl Effect works on are Sean Bean, Alec Baldwin, Will Wheaton, Martin Freeman and David Schwimmer.
"Hey, have you seen Joe? He's really rocking that new beard, makes him look totally badass"
Originally defined as 'Half way between a kiss and a blowjob"
You know the mouth movement one does when performing a blowie?
It's like that, except on the lips. Sucking someones lips instead of properly kissing. Often done when you're trying to make out with someone for the first time, although if the other person is doing it first time too, I guess you're Ok.