Hello :)
Read into Robert Kiyosaki's "Rich Dad, Poor Dad" books. He has great tips and eye openers for things like 401(k) and finances that has helped me out in the long run!

www.richdad.com

Depends.. A distributable event must happen to "cash out" the 401(k)
You must have left employment, reached retirment age (usually 59 1/2) or be permanently disabled. Just because you no longer contribute does not mean you can withdraw. If one of the above occurs you can close the account.
You also May have a hardship withdrawal option... the plan may or may not allow, and you would have to show proof of one of the qualifying reasons.. (eviction/forclosure, medical bills, college tuition, funeral expenses)
WIth any of the above you will have 20% taken out before the check is cut to you for federal taxes (401(k)'s must do this.. IRA do not have to) and if you are under 59 1/2, 55 in some cases, you will also have to pay an early withdrawal penalty of 10%..
Please let me know a bit more about the situation so I can answer a little more specifically....

This is exactly the info. I needed.