What it is: TweetDeck’s widget comes in a few flavors. The “bar” and “column” widgets show you whether you’ve got any new updates, messages or mentions, and lets you jump directly to that section of the app. The “post” widget, my personal favorite, lets you post an update directly from the phone’s home screen.
Why it’s a good widget: The “post” option works with both Facebook and Twitter, so you can have one widget that posts to either (or both at the same time). It’s useful for posting even if you use other Facebook or Twitter apps. [Free, Link]