Everyone is working on solutions for creating semantic descriptors these days. The Norwegian book shop ønskebok.no gives the user the opportunity to choose from a set of three descriptors and it will give you a list of books to choose from. Some of the adjectives seem to be based on words from psychological studies on emotions (e.g. happy-sad) while others are a bit more explicit (e.g. much-little sex). Anyway, it is great that we get some more human-friendly and semantically based alternatives to searching.