LOF (leap of faith) or NDA -- what would you do?

A friend of mine was recently approached by a startup founder to discuss potential employment or partnership possibilities. While this sounds like a wonderful career opportunity, he told me he was turned off by the founder's insistence that he should sign an NDA before they entered the conversation. Here are his arguments for why no sensible entrepreneur should sign the NDA in a situation like this:

1. How much the founder will be telling my friend about his company is solely at the founder's discretion. It is not clear what the founder is protecting against even before they enter the conversation. It only conveys a lack of trust and confidence, not exactly a turn-on during the "dating period."

2. When the start-up goes out to pitch VC firms for their funding, the convention is that VCs won't sign any NDA. Here is a starting point to research on this topic: http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=vc+sign+nda. For example, Brad Feld made some good points from the VCs' perspectives.

The irony is, clearly VCs will be more connected than an average employment/partnership candidate, and therefore bears a higher "risk" of "leaking" the start-up ideas to others. So why insist that the latter sign, but relax the rules on the former?

3. Here are some real legal concerns from my friend's perspective: The legal cases between Mark Zuckerberg and the Winklevoss brothers, or between Mark and Paul Ceglia recently are good entrepreneurial lessons that suggest one should never sign any NDA or contract casually. No one knows how the stuff he signed will affect his career 5 or 10 years down the road, right?

Well then, as a start-up founder, if you don't insist that people sign NDAs, how do you protect your ideas? Here are some heretic (read: non-scientific, non-data-driven) tips that are not taught in school: Be street-smart, and follow your gut feelings. If the candidate is a person you feel you can trust, then take a leap of faith and see where it leads you. Also, don't be too serious or overly protective with your ideas. After all, some say that ideas are a dime a dozen; execution is all that matters.