If you are a programmer, engineer, graphics designer, or business person, consider attending hackathons to improve your career. Most attendees just go for the prizes. Few are aware of this more important aspect. If you live in a large city you can attend 4 hackathons a year. You invest 4 weekends and often at no cost. Most are free, and they feed you. For that small investment, you add half a page to your resume by writing concise summaries of what you did. In a regular full time job, it can take years to make half a page of task descriptions. So hackathons are a highly leveraged investment.
There is much more. Often if you send your resume to a large firm, they run it thru a keyword check of their keywords. The higher the number of keywords in your resume, the greater the chance you meet their needs and thus the likelier they call you for an interview. But when you go to hackathons, you work on different projects. Just writing these up gives you more keywords and thus the chance of meeting the requirements of a new job.