The purple bike is a 32"... the first that I've seen in person. I think a 26" is the biggest I'd go after comparing everything from 23" to 30" wheels. Some of the bike that sit so low are on dropped suspension and sitting on the frame. Looks cool when they're parked but you could never ride like that. If I drop mine all the way I can still ride it like that which is good if the compressor stops working.
Frank, can you share a pic of a bike with a crotch rocket headlight?