Procrastination can be productive:
On http://fold.it/portal/ you can play a game and feel good about yourself: you are then not ‘really’ procrastinating, you are contributing for science. At least that is the way I do and it works!

Foldit is a puzzle game that helps to learn how proteins fold. Does not sound much? Proteins can be involved in disease in many different ways. The more we know about how certain proteins fold, the better new proteins we can design to combat the disease-related proteins and cure the diseases.

And in case you just watch TV for hours and hours, or do simply NOTHING, let your computer look for life on other planets:
http://setiathome.berkeley.edu/
http://www.seti.org/

Here you can find a list of projects from BOINC. BOINC is used by many volunteer computing projects. Some are based at universities and research labs, others are run by companies and individuals. You can participate in any number of these projects.
http://boinc.berkeley.edu/wiki/Project_list#SETI.40home