Our next tour is going to have several legs where we pack up the bikes and fly/bus/train/ferry with them. We're in the process of getting Bike Friday's with suitcase trailers. When traveling with our bikes and gear the helmets seem to stand out as space eaters. They don't weigh much but tend to take up a lot of valuable (and expensive) room.
I saw these BioLogic Pango folding helmets by clicking on one of their banner ads here. It seems it might alleviate some of that problem. They look a fair bit sturdier than the regular helmet, a good thing because I tend to kill helmets I tour with. I wonder if that's true.
Has anyone tried them?
Here's another view of it...