Czech TV is currently full of ads for "Casper's active absorbtion pad" which absorbs "up to 99% of gases". Yes, it neutralizes your farts! And it's supposedly "Bestseller in USA and Canada" (although I couldn't find anything through Google).
Have a look at http://caspers.cz/popis.htm. It uses "3D material based on space technology" and offers "solution to natural problems wherever you sit down for a long time". It can be yours for a very special price of just about $20. The question is: What can you do to prevent your farts from being heard? I guess there is still room for an improvement.