I want to improvise but I have nothing to record the chords over so is there a website that lets you put chords in a progression and play it?
I know of a site that has a number of progressions already, but you can't plug in your own. Jamcenter.com. Might not be what you're looking for, but its nice.
While looking at a guitar magazine with some friends.

Quote by Kaleb
DUDE! Is that a Mel Gibson?!

Quote by boreamor
Don't you understand the importance of correct spelling and grammar? It's the online symbol of maturity. And you as sure as hell don't have that.
Get Powertab (it's free) and write into it what ever you want the computer to play.
Like, this?: http://www.jamstudio.com/Studio/index.htm

I swear I have a link to everything.
“Science cannot solve the ultimate mystery of nature. And that is because, in the last analysis, we ourselves are part of nature and therefore part of the mystery that we are trying to solve.”

-Max Planck