Beautifying URIs
It’s not because URI are opaque that they should be ugly. Call me a Web-purist, but I manage to have opinions on the esthetics of URIs.
The single most ugly part of a URI is usually the query component (i.e. the part after the question mark), where Web-based applications communicate a varying number of parameters of diverse importance. The most widespread ugliness is probably these sites where any single page is with a URI à la index.php?page=welcome.