Link to Xfire Messenger: http://www.xfire.com/
Link to Xfire XO Toolbar: http://www.xfire.com/cms/about_xo/
What it does:
Web Game Tracking
Automatically track and share your web gaming history.
Web games supported
Videos & Screenshots
Take videos and screenshots of Open GL web games.
Easy access to the activity report, videos, screenshots and more.
Xfire XO works in the latest versions of Firefox and Internet Explorer.
What I noticed is that you don't *need* to actually play RuneScape for it to track your time because once you are at the RuneScape website it begins tracking your time online.
I guess what it seems to do is track the time spent on a website? Also it doesn't interact with the game at all in any way so would it be against Jagex's rule to have this installed? And can we get in trouble for it?
Also I'm not sure if it matters, but you need Xfire installed for it to work, according to what the website says.
Here's a screenshot of it when it's inactive (It just displays my user name).
Here's a screenshot of it when it's active (It's now displaying which game I am "playing" I'm not even logged in).