You can do this yourself, via a bookmarklet such as the 'linkify' bookmarklet on this page: http://www.7is7.com/software/bookmarklets/

Yes, it even works on iPhone or iPod Touch MobileSafari. (You can transfer complicated bookmarklets like that one by adding to desktop Safari, then using the bookmarklets sync option under the 'Info' tab in the ITunes>Devices>iPhone area. Beware, the first sync may clobber previous iPhone bookmarks with those from the desktop.)