Does your employer own software that you write on your own time at home? Can a client who commissions you to write software prevent you from reusing portions of that code for a different project? Are you entitled to modify software developed for you by an outside programmer? If you don't own copyright, will you have an implied licence to use software? Will an implied licence limit you to using software in a particular market sector or a particular jurisdiction? Does it matter how much you've paid for the software? Does it matter whether you've given / been given the source code? What about databases you commission from a third party?
Come to Bar Camp South East and find out. I'll be talking on the topic of "Who owns software?" - taking a practical look at the problems of determining who owns copyright and other rights in software and giving tips as to how you can protect your position.
[edited to add] I've since published an article dealing with these topics in more detail.