[malux85]

How about scaling? If you find something has already been done, then why not try making it bigger and better - yeah there's a library that can crawl a webpage, but how about crawling every webpage?

Yeah there's a library to recognise faces, but what about building a very quick search engine on top of it? What about one that can automatically spot celebs?

Yeah there's a library that can do substring matching using clever algorithms, but can you make it work in parallel across a cluster, can you achieve linear speedups?

Pick something that you find cool, then make it 1000 times bigger! :D