Windows: Like its original web app, the Inbox2 beta for Windows does a great job of combining your email, Twitter, Facebook, and other social messages into one sortable stream. It also respects your email labels and stars and adds simple task management tools.
To Inbox2's credit, setup is very, very simple. Enter in a few usernames and passwords, hit the authentication buttons, and everything starts streaming in. The benefit to a tool like Inbox2 is that you can take all your communication and process it the way you would email, so Inbox2 has three buttons — Todo, Waiting For and Someday — that help manage your communiqués and seem a lot like, well, the Trusted Trio.
Inbox2 also aggregates contacts across all your chosen accounts, which is convenient for reaching out to that person you know you know, somehow, but don't have time to hunt down. At first, Inbox2 only grabs the last 50 messages from each of your accounts, but a quick trip to the Options and you can download everything you've got, making the attachment and image aggregation tabs far more useful, and something like a social-media-aware Postbox.
Inbox2 is a free download for Windows systems only, but Mac and Linux users feeling left out can stick to the web app or Facebook application, launched from the same site.