I do this as well. I still check news, but the affirmative effort required limits consumption. It's not as advanced as some solutions but it's enough to keep me from getting distracted most of the time.

I wish I could easily block my personal email without blocking my work email, though (I use Gmail for both).

Also, using Pocket has been good for me. If I see something interesting on HN during work hours, I'll add it to Pocket and read it later.

It seems that changing your local DNS settings seems like a rather trivial barrier to get around but this technique is pretty useful. For me, procrastination is a subconscious habit and routing your time-sinks to "purple.com" is really eye-opening. Instead of just mindlessly typing in "reddit.com" and wasting 30 minutes before you realize it, you now get an immediate indicator of your intentions.

Just download reddit locally to circumvent having to remove it.