I just used an on/off lightswitch from Lowe's. If it wasn't so obvious in it's current position I figure it makes a marveleous anti-theft device :-)
BTW, you can but momentary push button swithces on eBay 2 for a dollar (including shipping):
http://www.ebay.com/itm/2-x-MOMENTAR...item3a6f2c3052