I've been analyzing myself on this subject lately because I'm trying to motivate myself to do things (like get in shape) and I was wondering what motivates others as well. I think it's interesting that things that can motivate one person can demotivate another.
For example, in regards to my weight loss, I've noticed how some people will put up posters or pictures of people who are where they want to be. I have a girl on my facebook who I used to go to school with who now enters body building competitions and she is always posting up women who are at her ideal physique and saying how she uses that for motivation.
I've noticed for me, doing that actually demotivates me. I get more sensitive to seeing thin, fit women when I'm making an effort to get that way myself and it makes me sad and uncomfortable to see them because it makes me feel like my goal is so far out of reach. What seems to motivate me is thinking of the short term goal as opposed to the long one. I'm trying to lose the weight I want by the end of the year and get physically fit within a year after that (since I know losing the weight and actually toning up and such don't always happen together). So to be motivated, I need to think about losing the 6 lbs that is my goal this month. Just 6 lbs. I'll be okay with 5. If I lose 5 lbs a month, I'll still have lost the weight I want to by the end of the year. So I just focus on this month and where I want to be by the end of the month. Having short term goals to focus on helps motivate me more than long term goals.
This applies to a lot more than weight obviously. I know some who will post up pictures of cars they want to encourage them to save up for it, etc.
What motivates you?