Unless you have really difficult ground conditions, I'd reccomend a t-post puller like the one BigDogues linked to. I pulled about 30-40 posts with the FEL last year re-setting some cross fencing. There were a few I couldn't get to very easily with the tractor, so I borrowed a t-post puller to get them out. After I used the puller, I went out and bought one for myself. To me, the time savings was worth the 40 bucks for the puller. By the time you align the FEL, position the bucket, wrap the chain, and pull the post, you could have pulled 5 posts with the t-post puller.
Every once in a while you'll get one that's stubborn and needs the power of the tractor to pull out. Except for those, three pumps of the handle on a puller gets it done!