A “MOOC” or “massive open online course” can be an excellent, low-cost way to demonstrate further interest in many fields, ranging from basic coursework to arcane topics, with many courses taught by renowned faculty at leading universities.  Some MOOCs to consider:

• EdX: https://www.edx.org/
• Coursera: https://www.coursera.org/
• Udacity: https://www.udacity.com/

Amazing Spiders