My cofounder and I have long agreed that most big company IP agreements suck (we've written about it at http://devver.net/blog/2008/08/looking-for-your-first-cs-job-be-sure-to-own-your-ideas/). Many of them state that employee IP, no matter when it's created, is owned by the company (whether or not that's enforceable is another state-specific question).
Now we're hiring (http://devver.net/jobs) and are trying to figure out a reasonable agreement for the IP employees generate in their free time.
On the one hand, we want to encourage our employees to work on what they want outside of work. They'll be happier, they'll increase their breadth of knowledge, and we want to support open source.
On the other hand, we do want to make sure we own the IP that directly relates our business (no matter when it's created). And since we want to hire full-time employees who are free to work from home, there won't always be a clear distinction between "company time" and "personal time."
Have any of you founders come up with an agreement that both encourages outside work yet protects your company adequately (and doesn't completely freak out investors)? I'd love to what different companies are doing in this regard.
Usually there is a blanket IP clause, but if I say "I'm going to work on ABC in my spare time" - and we all agree this isn't core the business - then it's added as a schedule exclusion.
You need to be specific, but it works just fine if all the parties are operating in good faith (which you'd hope with a good employee relationship).