How to disable Web Messenger on Microsoft websites?

Websites like SkyDrive and Outlook contain Web Messenger, which is a neat and useful feature, but sometimes I don't want it enabled. The closest I can get is being invisible, but even then that only shows my status as offline, and doesn't stop messages from coming in. If I'm in a place of buisness, and I need to grab a file off of SkyDrive, that doesn't prevent someone from chatting me something that could possibly get me fired from the workplace.