I was reminded again today how freaking awesome ClickOnce is.  Awesome to the developer, because you run a little wizard and get a deployment package, installation page,  and auto-update (and rollback) functionality.  Awesome for the user because you click a button to install an app, (maybe another to grant it permissions), and get notified whenever it updates.

To bad it doesn't work natively with FireFox.  Fortunately there's a plugin for it until Microsoft gets it working.  The first article also mentions a workaround you can use on your installation page.