Not mentioned in this article is the James Dyson Award. An annual international competition for students with a wide brief: "Design something that solves a problem...Products that have a significant and practical purpose, are commercially viable, and are designed with sustainability in mind."
The projects submitted are often very impressive and show great skill and ingenuity. The 2014 award went to a 23 year old student called James Roberts who designed a inflatable incubator for prematurely-born babies:
http://www.bbc.co.uk/news/technology-29900968
If you want to be inspired, the archive of entries is well worth browsing: