I looked into tracking via mobiles and unless you have a smart phone with a sat nav application built in, the only method I came across was not possible without the knowledge of the user. In short, they send a text message to your phone asking you if it's ok to respond with your locaion. if you decline it is apparently outside the law to do so. Depends on how unscrupulous your boss is perhaps!
To tell if you're being tracked, try taking it to work with you but telling the boss you've left it at home. Then go and do something you shouldn't!!