If you have never heard of it, check this linky:
Semenex Web Site 
[Edit]: Link may be NSWF like many things on this board
Basically, it is a concentrated supplement that is supposed to make the taste of your semen sweeter/more palatable.  Obvious benefits on both sides if it makes oral sex more pleasant for her to give.  
I am wondering if there is anyone out there who has tried the product and can provide some feedback about it.  I am considering trying it with my wife, but I'd love to hear an impartial third party.  
I will probably order some and try it out anyway.  It is only $20-30... it just might be the best $30 I ever spent if it works as advertised.  I might report my findings back here once we have done some field testing.