Get the attention of a remote user

I regularly use LogMeIn Rescue to provide remote support for users. Sometimes they stop paying attention while I'm working and when that happens I'll inevitably end up needing to get them to enter a password or otherwise interact with the computer. One nifty trick I use is to repeatedly set their volume using the Windows 7 volume control in the taskbar. The computer will beep each time you click a volume level as a test sound and a few times in a row will typically get someone's attention pretty quickly!

And if that doesn't work, there's always BreadFish