Actually, not easy. I tried that. I asked the front desk to call for an HR manager or recruiter. After 20 minutes of calling around, I had to leave. Cold calling does not work well for job searches.
For employment based green cards (EBx) the applicant may use his/her EAD to work in a job that is similar to the petitioners I140 case (this is known as AC21). I can't go from Design Engineer on my H1B to CEO on my EAD :(
Thanks Dani. I am aware of the O-1 visa. However wait times are about 1-2 years to get it (the same as an EB1 green card). I think I might have a case with my background. Thanks anyway!