Also don't fall into the trap of thinking that dongles are un-copyable. I used to work in the oil industry and our software cost $50,000 per license and was protected using the leading hardware dongle at the time - we still found copies of the software on sale in Shanghai complete with fully working faked dongles.

Sometimes I think the best security is obscurity - if you use a widely recognised system the chances are that someone will have found it worth their while to identify, analyse and crack it because it will then open the door to many different products, whereas if you are using a unique form of security unless there's a compelling cost/benefit advantage for someone to spend a lot of time on your own specific case to try and break it.

I'm now working for a company where our products have in excess of 500,000 users in the UK alone and our security can be (and has been) readily cracked because with a market that size it is worth hackers spending as long as it takes to get around it.