If you are planning to look for a job rather than start a company, you really should get your degree.

If your classes are not stimulating you enough, perhaps you could try training for programming competitions (TopCoder, Google Code Jam, ACM ICPC). Doing well on those could be a good differentiator on a resume.

That's naive of you. You can't just fly in the states and interview for a job. Without a green card, you can only stay in US with a tourist visa for 3 months max, or with a student visa if you enroll in some university over there and pay their thousands-dollar tuitions (but you can't get a job), they're very strict on immigration policies. Oddly enough, it might be easier to get a full permit if you start a company, but I guess you'd have to prove that you're investing (bringing in) a substantial amount of money.