A visual dictionary/wiki for finding the names of obscure things. Users could submit definitions and pictures. They could also tag pictures with the names of related things so you could search based on objects that are commonly found near or work with the thing you're looking for. The picture would help you confirm you found the right thing.
For example, suppose you didn't know what the little plastic thing on the end of your shoelace was called and you wanted to buy more of them. You could search for "shoelace" or "end of shoelace" and find a picture of an aglet. Maybe even some ads to where you could buy a supply of aglets. Now, no more frayed shoelace ends for you, and life is a little better. :)
Visual dictionaries (including online ones) already exist, although according to one ( http://visual.merriam-webster.com/ ), the aglet is actually called a "tag".
For example, suppose you didn't know what the little plastic thing on the end of your shoelace was called and you wanted to buy more of them. You could search for "shoelace" or "end of shoelace" and find a picture of an aglet. Maybe even some ads to where you could buy a supply of aglets. Now, no more frayed shoelace ends for you, and life is a little better. :)