We’ve seen a number of Twitter tools for scheduling future tweets, shortening URLs, and tracking click-thrus. But BrightKit (not to be confused with the location-aware app BrightKite) is the sleekest we’ve seen yet, making it worth a mention.

What makes BrightKit special is its beautiful interface for managing multiple Twitter accounts. The Dashboard lets you see all your Twitter accounts at once, while you can also use a pull-down to toggle from one to the other to utilize all of BrightKit’s options. Those options include scheduling Tweets for the future, viewing your pending Tweets, automatically generating short URLs (of the ow.ly variety), and seeing click-thru data on your messages.

You can also setup multiple admins for your BrightKit account, which makes sense given the service is targeting businesses that want to use Twitter. Here’s what it looks like:

BrightKit also has some intriguing features planned, including geo-location tracking, exportable reports, and offering users the ability to reply directly from within the interface. Unlike many tools that are simply side projects of developers, this one comes to us from an interactive agency called Invoke.

Similar tools include EasyTweets and Twuffer. EasyTweets recently added some new features that BrightKit doesn’t offer yet including being able to view the timelines for all of your accounts, a bookmarklet for sharing links, and integrated search. But we think BrightKit has the best interface at at the moment and recommend it if managing multiple Twitter accounts and creating the illusion of never sleeping are high on your priority list.