To the bikefest, yes I do but it's done for this year.
Leesburg Bikefest - Home Page
I did an on ne search and there are lots of places with specialty horns. I also found a whinny ring tone for your cell phone (yours not mine thank you)
I figure if I looked through all of them I'd eventually find it. At work now do don't have time but if I figure it out, I'll let you know.