How do you keep your motivation.....at work?

I was asked to speak about this topic shortly after starting Blog Talk Radio. I said I would so here goes. The person wanted to know how to keep motivated at work. I had to marinate on it because we all have those not so good days where we just are not feeling it! What do you do? Do you work in a negative environment that makes it hard to stay positive and motivated. What tips do you have to give to someone who is struggling? I will share what I know and hopefully shed some insight on what we all deal with at one time or another