Saw a good example of this at http://cicerontheme.tumblr.com/. You can like a post from the homepage without having to go to the permalink page.
Here's what I've found from her source.
I'm gonna go get some Chipotle and I expect this to be answered by the time I get back.
Hopefully it takes you 3 weeks to get Chipotle.
So I got chips and usually order two sides of guacamole cause the chips are too many, but what the f*ck is this - fewer chips and too much guacamole!
http://stackoverflow.com/questions/6970156/tumblr-like-heart-button-script-on-homepage?
yeah thats where i found it actually, but it didnt explain much past the js part.
ay, ay! ??????
21 DAYS, C'MON
2 months.