Majority: High tech industry: team based software development and QA/testing
1) Non-high-tech: applying CS skill sets and technologies to other disciplines (medical, bio, econ, …)
2) Start their own companies (become entrepreneurs) or join startups
UCSB offers a TMP program and classes that you can take to learn how to do so:
3) Pursue higher degrees (MS's and PhDs)
We offer a 5 year BS/MS in our department and college: http://engineering.ucsb.edu/current_undergraduates/pdf/coe_five_year_bsms_brochure.pdf
We can also help you set yourself up to pursue a PhD in computer science.