Time management problems

Lately I was so busy with the school and work assignments that I end up doing this all day : work/school/work/sleep/…, this kinda took me down mentally and physically ( and as a bonus, quarrels with my girlfriend ). The problem with my work-related time is that I switch the applications very fast between FireFox ( most on Swirve’s Utopia, a text game that I play since 2001 or so ), WinAmp, PHP Designer and Yahoo Messenger even thought when I’m at work I should open ONLY the programming tools; so instead of working 3-4 hours per day I end up sometimes working only 50-75 minutes even if I stay a lot of time in the front of the computer.
There are simply too many sources of interest on the Internet to concentrate on my projects , so most of the time I stay all night awake to finish the projects on time instead of doing them during the day.
After reading a friend’s blog I saw that a theoretical solution exists, it is called “Time Management”, I went to biblio.com and searched for the book recommended by him : Getting Things Done: The Art of Stress-Free Productivity, written by David Allen.
I bought it for about 12$ and in 6-7 days I should have it and start reading ( I have already read few free pages from it and I really liked what I read, that’s why I bought it ). Let’s hope it will help me.
Anyway … I’ll write down my opinion after I finish it.