I have used, with success, a product call 'Dinkey Dongle'. I have used two versions: the first was parallel port based, the current is USB. Very simple to use as a 'wrapper' around your application. For a little more effort embedding it in your app, you can get significantly more security. Highly recommended. Not sure about $$ in your QTY. Bob Ammerman [a copy sent offlist to James as he was the original poster] -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist