[mattgibson]

Generally, you can ask for these clauses to be taken out of the contract when negotiating whilst interviewing. They are often just part of a boilerplate. Directly competing products seem like a fair thing to want to restrict, but other stuff with blanket IP assignment can be removed.

I am currently working as a contractor and the interllectual property assignment clause mentions "materials created pursuant to this agreement", but nothing further than that.

If they push back, point out that such clauses are illegal in California and it doesn't seem to have held back the companises in silicon valley too much. You always have the option to walk away if they won't agree.