Is there a keyboard short-cut to quickly open a URL from the Finder? On my Windows machine I use [Win]+R to bring up a RUN prompt where I can type in a URL to quickly go to the web.  

I've been searching to find a Mac equivalent (without installing any special software) and haven't had any luck.  Is there a Mac equivalent?
Assuming you're using Yosemite, Spotlight can do this. Cmd-Space, type in your address, hit enter. I can't confirm if this works in older versions of OS X though.