If the URL could be of anything, you could probably best chose to strip the middle part (as others have noted). If a URL has been properly constructed, the end will have the title of the page. The first part is important because it indicates the source. This would be a good reason to try and get the entire domain in. Also be sure to show the full URL (or as much of it as possible) in a tooltip!
Addittionaly, you could tweak the URL even further.
lose the http://. Users shouldn't usually be concerned with the differences between http, https, ftp and what not. Also, other aspects of the representation will make it clear this is a web address.
lose the www.. It is not a differentiating aspect of an address and saves space for 4 more interesting characters.
I would take it one step further and retrieve the title of the referenced pages. This a more humanly readable indicator of what the page is about. Google primarily lists page titles for a reason ;). Do add the url as secondary information of course. Titles can be long too (I've seen people put the entire first paragrph of a page in the title, presumably in an attempt at SEO), so truncate these at the end.
Open Device Labs: Why Should We Care?... (smashingmagazine.com...ould-we-care/)