Time Tracking Tools

We’ve acquired a new engineering manager at work so at long last we’re starting to put in place some of the things we’ve always said “we should do that” about for a long time but never actually gotten around to doing. One of those things is establishing how accurate our estimates are by actually tracking the time taken to complete the task. Other metrics may be useful later, but for now we just want to track time taken since time is our most limited resource. The trouble is, I don’t know of any really good time tracking tools. Here’s the rough requirements:

• Must keep track of time taken on multiple jobs, some or all of which may be in progress at the same time.
• Must have some way of mapping the job back to it’s original assigned ID (probably a bugzilla number but could be a netsuite number, scarab issue or who knows what – we haven’t sorted out how to track tasks well yet).
• Preferably runs on OS X and Windows, OS X only is okay, Windows only is bearable, Solaris only is usable but not ideal – anything else only isn’t any use at all.
• Preferably provides a very simple way to start and stop the timer for a task. I get interrupted a lot during the day so it would be good to be able to “hit the pause button” with a simple keystroke, ideally without having to bring the app to the foreground first.
• Needs to export to a format that can be manipulated. XML would be great, CSV is also good, funky proprietary text based thing that I’ve got to parse is okay, funky proprietary binary based thing is no good. I’m thinking this is probably something I’ll wind up writing myself so that it works just the way I want so having the source code available would probably be a benefit as well. That way I can tweak instead of write from scratch. So, any suggestions? What do other people use to track development metrics?