Here's an excellent article I found which dispels the notion that you have to work long hours in order to be productive.
Some take aways here:
1) Talk to your boss about what measurable results he expects of you.
2) Cut interruptions. Good way to do this would be to shut-down your office communicator, phone or mobile during your 'do-not-disturb' work hours.
3) Make meetings focused and short
4) Substitute travel with WebEx and conferencing.