I came across some really good productivity tips this past week. One group in a great post from Matt Heinz and the other in a post from Erin Schulte from Fast Company. I'll add two things to their lists that have worked really for me:

Each morning I write down my top three priorities for the day. That is, the top 3 most important things that I need to accomplish that will help me get to where I want to be. I actually capture these in the Chatter app in Salesforce.com, but you could capture them anywhere. Then, at the end of each day, I update the Chatter post confirming that I got them done. You'd be shocked at how productive you can be if you only do the 3 most important things on your list each day.
To prevent myself from spending the day responding to incoming streams of messages, I work 'offline' for large portions of the day. I put on my headphones and close all web browsers and switch to "work offline" mode in Outlook and go to work. These are typically the the most productive parts of my day.

I'm sure I have others but those two stand out as things that have really helped me ramp up my productivity in recent years.