Wow, I didn't read your responses, but I'm sorry for you that everyone was so off-topic. I can relate to your issue. We had our son circumcised, first because my husband is and I felt it was appropriate for him to make the decision since he had the experience, but also because I was under the impression, like you, that he would be an oddball in the locker room if he wasn't. Now that I've seen friends and strangers change their sons' diapers (not that I look, mind you!) I know that that's just not the case anymore. I felt horribly guilty once I realized what a circumcision actually was, and what it entailed. I did not educate myself beforehand. I even brought it up with my mother and aunt, and found out (too late) that NO BOYS in my own family are circumcised! My grandfather was the firstborn American in his family, the rest having come from Europe, so he was not circumcised, nor were his 6 brothers. Neither was my uncle and neither was my cousin. I felt like I should have been made privy to this information before I decided to change the trend.
Anyway, when I got pregnant with our second child, I told my husband that if it was a boy, I was really going to have a hard time with the decision - I wouldn't want our children to be "different" from one another, but I also wouldn't want to make the same decision, knowing what I know now. I just didn't feel good about it. Luckily, we had a girl!
After having our son, I read a book called "It's a Boy: Women Writers on Raising Sons"
http://www.amazon.com/Its-Boy-Women-Writers-Raising/dp/15...
Among other wonderful essays, there is one entitled "Making the Cut". It is very well written and it states, simply, both sides of the issue. It helped me come to terms with my decision. You should check it out - it offers some good perspectives.
You sound like a very loving mother - don't beat yourself up for this. I think you did what you believed to be right, so in the end it was the right thing to do.