NDA "Prior Inventions" Claus

BenderMan writes: I own a small consulting company. Today I was asked by yet another corporate customer to sign an NDA with the increasingly popular "Prior Inventions" clause. The gist of it is they want you to provide a list of all your past and current inventions and/or ideas so they can define and protect the intellectual property that they have hired you to build. Like many of us that lay awake at night, whilst the hamster wheel spins new ideas, I've got a number of unpatented works in various stages of development. Given that mutual NDAs only provide one year of protection, I don't feel obligated, nor do I have sufficient time and energy, to fully and properly document my inventions for an NDA. While these clauses are written with good intentions, the reality is that these valuable ideas would be placed in the hands of people that could potentially profit with impunity (Have you priced patents lately?). Unfortunately many companies are not willing to strike this clause from their contracts. Do Slashdotters agree that this is a concern, and how have you dealt with these situations?