For those who haven't heard about the holland code. It's basically a system to measure your interests split into 6 subsections - Realistic/Investigate/Enterprising/Social/Artistic/Coventional. It's there to help people discover what sort of profession they want to go. Various tests can be found on the internet such as...
Holland Code Quiz
Oxford CareerFitNow Analysis
Also what profession/Degree course are you in?
Current study: Geology & Geophysics
Desired study: Psychology
Profession: Err... something in that field would be nice or education.