(Obviously it's not just me. Blame the internet, it's re-wiring our brains and turning them to mush.)
Sooooo, maybe it's silly that I'm about to link to a website, of all things, that might help de-mush you. ...What can I say, I contradict myself. I am large, I contain multitudes.*
Okay. Raise your hand if you've heard of the Pomodoro Technique. Now put your hand down, because I can't see you anyway. Now put it back up. Now back down. (Just making sure you're still paying attention.)
Now high-five a million angels, because this technique is awesomesauce.
The Pomodoro Technique was created by some guy named Francesco Cirillo (yeah, I'd never heard of him either) and the gist is that you work in 25 minute increments (a "pomodoro") with 5 minute breaks in between. You pick a task before you start, and then you just. do. that.
You don't answer the phone during a pomodoro. You don't check your email. If you think of something you need to do that's off-task, you jot it down and deal with it on break or during another pomodoro. And what's cool is, it's easy to stay focused for 25 minutes when you know you get a break at the end - it's like you trick your brain into it by saying, "Hey, we just have to get through this one thing, then PARTY TIME!!!!!" (There's also apparently some kind of pseudo-scientific-ish brain-rhythm thing going on, but I don't know much about that.)
The original technique calls for a kitchen timer, but I've found something even better:
Register and behold: productivity abounds.