Its pretty simple really.
1. LEARN how to properly use outlook, calender features, address books, planners
2. Get a GOOD project management system, there are even free ones out there, one would be
http://www.opengoo.org/
3. USE YOUR TOOLS
Staying organized is easy, that is IF you take the time to stay organized.....99.999% of people get the right tools and then NEVER use them.
Especially in our business this is our biggest problem!
EDIT: Plan out your day every day....dont just sit donw and go nuts, its not productive and will lead to chaos.