Both Twitter and Pandora have a massive user base. What happens when you mash both of them up? You get Dora.fm. Dora.fm lets you send out a tweet that shows what you are listening to on Pandora. You can add replies, RTs, or general messages about the track at the bottom of the website.
To mash the two up, It appears that Pandora is placed in an iFrame. Generally I’m not a big fan of iFrames, but this seems to make great use out of them. [ReadWriteWeb]