Sudha,
What some people do is to contact their former employer, or another company back home to arrange to do work for them over the Internet while they are overseas. They are paid into their own bank account back home and continuing all their "back home" deductions, social insurances, etc.

It saves considerably on complications (like having to get a US social security number) and while it isn't strictly legal, it seems to be an area where the law hasn't yet caught up with the technology so it's unlikely anyone will give you a hard time about it.
Cheers,
Bev