" H1B visa holders can change employers as soon as a H1B petition is 'submitted' to the INS by the new employer "
New H1B bill approved in the senate and House
The senate voted 96-1 to approve the new H1B bill S.2045
The House of Representatives passed the H1B visa bill (S. 2045) on a voice vote.
http://www.techlawjournal.com/cong106/h1b/s2045_20000309.htm
http://www.unk.edu/international/scholars/H1B/index.php?id=2789