While bookmarking a page to Diigo, you can now choose to upload and capture a snapshot, using the Diigo toolbar.  Snapshot ~ it is best for important or temporary pages that you really want to preserve, and also for pages that are behind password. PDF and other online file formats can also be uploaded.

Once submitted, you should see the snapshot in your library within seconds to few minutes or so. You can take snaphots of the same url at different times, if you are interested in seeing how the page changes over time.