It's really a lot of fun. Here's one way to do it. Download the song that the icecream man uses and loop it on a CD, then SLOWLY roll through neighborhoods blasting it with the windows down. The kids hear the song and instantly freak out asking their parents for money and come running out of their houses at full speed, only to see you driving away laughing. You can feel the disappointment in their eyes and soon you can even see tears in some of the more fragile children. OMG it's so funny, you have to try it.
Sober enough to know what I'm doing, drunk enough to really enjoy doing it