Ideas that make life easier
Music finder through similarity
User inputs a song and defines the wanted similarity (similar beat, similar mood, similar harmony, similar melody). The software returns all similar songs until a defined threshold.
User defines the desired song structure (fast intro, slow chorus, etc.) and filters for generes.
Ideas that advance understanding
Discussion partner finder
A meta discussion platform, where the ideology of participating users is analyzed through NLP. Users can then request to discuss (about various topics) with partners according to their ideological distance. In other words if you really wanted to, assuming you're a hardcore atheist, you could request to discuss with someone with the greatest distance on the topic religion. You'd end up discussing with a intelligent design fanatic :P