I rip the article or page referring to the website and put it in my inbox. When I process my inbox, I'll either:
A) add the URL of the site to a list in my Someday/Maybe called Websites to Checkout (I keep the URLs in the notes area).
Websites to Check out:
As I check them out, I'll remove them from this list and then:
B) I'll check out the site quickly and Bookmark it or discard it if I'll never use it.
C) When I actually do visit the website and I need to save the info for future reference, I'll store it in Yojimbo (which I process at my weekly review also). Yojimbo is a similar bookmark program that allows you to archive websites (on Mac OS) and then sort the archives or bookmarks into their own categories, which I then use as Project Support Materials.
Hope that helps.