When I saw a post about Klok on DownloadSquad I immediately thought that the idea is brilliant. Now that I've used Klok for 2 days I can say that implementation is a little rough around the edges but definitely useable and the idea is really brilliant and not only on paper but in real life too.
So, what is Klok? In it's creator's Rob McKeown's words:
Klok is a tool intended to be used by individuals, like myself, who have a need to track the time they spend on projects, tasks or anything else for that matter.
There are many project/progress tracking solutions out there but for tasks when you work alone or you are not a project manager needing to track activity of multiple developers using something complex is an overkill. When I needed to track time spent on some project most of the time I've resorted to post-it's or spreadsheets and system clock but with Klok I can save trees and my own time. And, by the way, it can export your timesheet to Excel, too.
Basically you just have a small bar on your screen
and select a project you are currently working on. And the stopwatch starts. When you are done with the project you switch to other project or just hit "stop". Projects can have sub-projects and sub-projects can have sub-sub-projects and so on. Then you can view your week in calendar-like fashion. Or look at your data on project basis. Or generate reports. Or export data to Excel.
Not everything is pink in Klok: I wish it was just a tray icon or Vista SideBar Gadget rather than bar shown above, I wish there were some configuration options (a week doesn't start on Sunday over here), the UI isn't perfectly smooth and for reasons unknown not all projects are shown in project dropdown all the time. But all these are minor issues which I believe will be addressed over time because overall this is a really nice add-on to my toolset.
You can find Klok at http://klok.mcgraphix.com/
P.S.: I was somewhat skeptical about all this Adobe AIR thing but now I'm already using 3 AIR apps on a regular basis: twhirl (which is probably one of the most beautiful and polished little apps I've seen), Pandora (well, it's actually a website shell but still) and now Klok.