Here's the Plex Video Plug-in by our friends Alexander Danling and Anders Olsson. Currently it lets you browse in your Put.io account and plays files playable by Plex. It's a pretty luxurious way to consume your media on Put.io.
Plex is a Media Center Application for Mac OS X and iOS that allows you to play your online or offline media on your Mac connected TV. It's based on XBMC. Download Plex from http://www.plexapp.com for free.
Note: The app will ask for your API Key and API Secret, not your username and password. You can find them on your Account Settings page