What you do is this. In Safari or Firefox or whatever your favorite browser is, create a new bookmark, which I include here for your copying pleasure. This bookmark comes courtesy of Coldbeans software and what it does is converts the URL for your current page to a QRCode and displays it in a floating window.
From the iPhone side, use any of the millions of free QRCode clients to scan your computer. Instantly, the URL transfers, allowing you to copy it, view it, send it in email, etc.
Victor tells me he uses this to load up his iPhone with amusing YouTube Videos, but you probably have far more respectable reasons for transferring URLs.