How do you hook the auto updater within an application? I wanted to add a "Check for updates" to the tool bar in my application and leverage the click once auto updater.

I'm assuming your application is ClickOnce deployed to begin with. If so you can use methods available in the System.Deployment.Application namespace to check for updates and download updates programatically from within your app.

For more info see:
http://msdn2.microsoft.com/en-us/library/ms136930(en-US,VS.80).aspx

Regards,
Sameer

Something like this right?

System.Deployment.Application.ApplicationDeployment ad = System.Deployment.Application.ApplicationDeployment.CurrentDeployment;