FYI, just so you know, alot of people have told me that a neutered male makes the finest house pet. Spayed females generally get fat and un-neutered males mark their territory alot and tend to roam more than neutered males.
I had my dog neutered this week and was feeling a little guilty that I never could have one of his offspring. The trainer I'm working with told me I did the right thing... he'll be more docile and less prone to certain cancers.