What is your Carrot? (Motivation)

On Monday before Winter Break, (the last full day of classes) I learned something about motivation. Everyone came in to class asking if they could play that game (armegetron) again. Some students told me they would do anything if they could play that game again. So I switched up my lesson plan. I opened a keyboarding book with sample projects and turned to a Business Letter. We practiced Keyboarding for ten minutes then I told the students that if they wanted to play the game today they needed to key the business letter first. I have never had such a good response. Everyone worked hard. They Keyboarded the assignment quicker than they have done before, and with the exception of two people the letters were done correctly.(which is the highest return I've had yet.)I had one student that has refused to turn in or do any assignments for the entire semester keyboard and turn in the assignment. He came up to me very proudly and declared look I did the work, he was so happy that he did it. I was amazed this was a student that normally sits and stares at the computer until the bell rings, or tries to get kicked out every day. He was excited to Keyboard so he could get to the game. I have never seen the students so motivated, they were so excited everyone wanted to play. It was crazy. The teacher that shares my room was in during his prep period and he told me I may have discovered a secret to the students motivation. He told me if I could harness that desire and get them to work like that often it would be great. He told me of a production company he worked for that the employees wanted 3 days off for hunting, the company allowed only one. Then a foreman came up with a motivating idea. During that week when the workers hit the weekly goal they were finished for the week. My coworker informed me that they hit the goal on Tuesday every year during the hunting week. The products did not suffer, they were still made with quality but the workers had some extrinsic motivation that really made them work hard. This was the same with my class I was able to get them to keyboard more quickly and accurately for many of them because they were motivated. I am now trying to find external motivators that help me out so that I can work much harder. This Winter Break I am working on finding a lot of external motivators for the students. Does anyone know of non-violent free or cheap network games? Any other suggestions on how to motivate students? Please post comments on any ideas you may have to motivate students.