I used a trimmer belt for awhile and ever since I put it down (I never use it when I'm back on my heavy lift due to the wearing of a squat belt) and it worked great. I works like those odd "garbage bag" suits you may have seen people wearing but focused on the mid section. You can buy them at Wal-Mart in the fitness section, Dick's Sporting Goods and so on. You just have to keep active, wear it when you work out.
It focuses the heat you develop during a workout directly back to your abdominals which both "melts" the fat in the area as well as stimulates the muscle itself. You won't develop a 24 pack just from the use of this.
Your hardest spot to cut will be your lower abdominals so it's key to exaggerate a lower abdominal workout more than any other abdominal workout (throw more workouts in, more sets, more reps than any other abdominal workout). Decline sit-ups, leg raises, heels-to-heavens, flutter kicks, etc.
Kill push-ups and improvise a way to "fly"...since you don't like gyms it may be a little hard to do. Do push-ups from every motion, decline, flat, incline. As far as flyes kill those from every motion, whether you buy weights or just use something heavy laying around the house.
Invest, pirate, or borrow P90X. It's more for those that are out of shape or into cardio than the heavy lifters (I did it and lost a great amount of mass but was pretty cut).
Since you hate gyms, just get creative. I'm going to be going to school in Virginia for the Marine Corps which is going to require a lot of my time. Which means I won;t be hitting the gym. So, for the 4 months that I'm cooped up in a hotel, I plan on doing P90X, getting a kettle bell and doing crossfit, cargo strapping my bed for decline sit-ups / bench press (cargo strap weight to the bed, get under and lift), and using a TRX resistance band...
TRX - http://www.fitnessanywhere.com/
Crossfit Demos - http://www.crossfit.com/cf-info/excercise.html
General Workout Demos - http://www.shapefit.com/
If you hate gyms man, it's going to be difficult. Hopefully all this will help you out.
EDIT: Forgot to mention, which those before me who have but I wanted to emphasize is diet. I used to be huge into diet but it go so F-ing boring and bland so I settled with a decent body for happiness of eating. High protein, moderate carbs, low fat if your looking to shred fat. Up the fat content once you get them pecks and abs going to a moderate fat content (avocados, fish oil, egg yolk, cottage cheese, [more] peanut butter)...I can make you a diet plan, but it gets pretty bland after awhile....I hope you like chicken breast and brown rice.