I am also the kind of person who gets distracted rather easily as I have a really broad spectrum of hobbies/interests. I've tried some similar approaches without much success.
Back in old days when I was still a graduate student, I had a paper deadline due in a few days, but I was addictive in Slashdot discussion then. I experimented fully command line work environment: no browsers, no X-windows, only a few linux consoles you can switch among by pressing Alt-Fx. The transition was painful, as I had to look for command line equivalent to view pdf/ps/eps files, gdb is not as convenient as ddd, etc. However, my productivity gain was enormous, at least for the first a few days. The curve quickly flattened and began to fall, as I started to use command line browsers such as lynx/links and I discovered a few legacy games.
Another time I went even further: screw the Internet! I installed Slackware onto an old dell notebook and uninstalled all fun games and apps, unplug the wireless card and went to the public library nearby for a day. Almost the same result, I had done lots of task at an amazing speed initially. Then, I got bored, and wrote a frame-buffer based Galaga-like shooting game and played/improved it for the rest of the day.