ITV have recently (at least I only recently found out) started making all four of their channels available almost live on their website. Whilst this may turn out to be useful, especially as I can't get the other three channels where I live (no freeview signal!), I'm more impressed with their Best of ITV section.
In essence they are allowing us to watch some of the best dramas they have previously funded. So for example you can watch the first series of Cracker, Cold Feet, Cadfael and many more whenever you want! While the quality may not be such that they would be watchable on a TV screen they are perfect for watching on the PC while pretending to work.
Even in the week or so since I found the site they have added new content so hopefully they will continue adding more and more great British dramas for us to watch. Unfortunately it seems they are currently only providing the first series of each drama, although hopefully this will change in the future.