My husband and I are in US on our respective H1B's both of which are valid until Sep 2011. Both of our H1Bs were obtained against the respective year's H1 quota. I went from a F1 to H1 visa in Oct 2008 but since I haven't left the country, I don't have a valid visa stamp. 3 questions:

(1)If I quit my job today what do I have to do to get on a H4 visa? Any paperwork? Do I have to leave the country to get a H4 stamp immediately?

(2)Lets say I get on a H4 and some months down the road I get another job. Will I have to go through the H1 cap again? Or can I reuse my old H1 visa validity to join the new job ASAP with a H1 transfer? Can I start on new job without time and H1 cap restrictions?

(3)Is there a timelimit to how long I have to reuse my old H1 (while on H4)and avoid the cap?