Twitter's web platform is easy to communicate with and includes a powerful API that allows for the creation of applications that take the platform in directions well beyond sending 140 character or less shout-outs to friends.

For example, a one could use Twitter as a time clock service by pinging Twitter via SMS, IM, Facebook, or directly through Twitter.com whenever you want to punch in/out of work or a project. You could set up a Twitter account for each of your projects, then send direct messages to your project name every time you want to log in or out. Quick messages such as, "d acmewebsite in" followed by "d acmewebsite out" would stamp your time in and out. The client could track your hours by subscribing to their RSS feed of the project. And a custom time tracking application could be built to access that data and roll up the hours by individual attached to the project. You could even include short project notes with each message.

W. B. Mook has done something similar, but didn't go as far as direct Tweets to projects, thus created irrelevant content for other subscribers:

Better things to Twitter about - Watercooler to the World

Punch the Clock For a while, I was using twitter to log my time, since our time clock web app cares mostly about the time you started working on a project and the time you finished, rather than just allowing you to enter a certain number of hours on a certain task. Useful, but boring to your readers.

So it can be done, but is there a market or such an application? Perhaps scrappy start-ups would see this as a way to track who's working on what and when. It seems likely that someone could build a subscription based service that provides a clean interface for time calculations which also provides for editing missed or mistaken check-ins.

At this point, I think the market for this is limited to freelancers. And I'm sure there are plenty of Twitter users who bill or their time on a consulting basis who would love to be able to Tweet their billable hours. The market for a service like this would surely grow as Twitter becomes more mainstream.

I think the real beauty of this is people could use the service for time tracking purposes without gumming up their relationships - personal or business - by using direct Tweets. Only those on a need to know basis would see this particular use of the service.