I've never been real big into the fat burners, I just don't trust them. If I didn't have one and was looking to get one I would do a few things. I would make sure that I was on a good diet, trying to cut some calories. I would also make sure that I was taking both a pre-workout and a protein. Pre-workouts will have the kind of stimulants that will get you to not only work harder in the weight room but also usually help speed up your metabolism. Then, the main thing is to be doing a lot of abs. The initial six pack can take some time, but, depending on where you are starting, you can get there quickly by making sure that you do at least a couple hundred ab reps each day and you will eventually see good results.