My friend who has this setup has a machine that will run with an on/off button in addition to the foot pedal, but I'm sure that lots of folks have this setup with a machine without that option. If you are purchasing a new machine, you might want to look for this feature.
Here's a previous post:
http://www.quiltingboard.com/main-f1...lp-t61368.html
Here is an interesting ebook on setting this up and various power options:
http://ebooks.kathyquilts.com/Machin..._Magic_1.0.pdf