I would do it for immortality, at least until i can design a device which works based around my brain waves to 'freeze/unfreeze' anyone or anything i want, giving them immortality aswell, but they can't use my device BTW. Also, I have to focus on it and I cannot freeze myself (as that would suck because there would be no one to unfreeze everyone)
EDIT: After I could do whatever I want, including bring people in and out of time freeze (otherwise I would eventually get bored and this way I never age but still get the benefits of having other human beings around), I would pull funny pranks (and then unfreeze the people and objects involved so I could watch it without aging), manage a large garden (Simply for the pleasure of eating as I would freeze/unfreeze my digestive system to suit the needs for food consumption).
Though I do have a question, how would I get enough food to live forever and how would I have enough energy to move things when time is zero and whenever you divide by zero people say you get infinity??? (don't worry if you don't get the reason for teh divide by zero, it is aimed at people who have done kinematics)