Check the web to see if there are updates to the gadget. The gadget checks for updates every 24 hours (or on startup.) If there is an update, the webcam area shows a link to click for more information about the update. The user will still have to manually install the new version, but this will be a very easy way to communicate the changes to the user base. It's also a nice way for me to know roughly how many people are using the gadget since it checks a specific file once per day.