A lot of it depends on where you live and how high up you are in the company too. If you're a VP or a director, your expectations and legal burdens and considerations are often different from Bob Joe programmer or Larry the phone guy.

For example, in my province, non-competes were banned a couple years ago. I started work with an employer a year prior to that ban, and they had a stealth non-compete in my contract, but basically the rest of the contract was unenforceable anyways.

As always, it's worth learning your rights and seeking legal advice prior to signing any legal agreements like contracts.