This is an idea for your regular type of baseball cap, but when you pull a string on the side, two layers of fabric covering the hat draw out from the frame of the hat and with a simple twist of the knob at the very top, the layer on top slides over the spaces created by the new outstretched conformation thus creating a more shady umbrella-type hat.
Still don't know exactly what to do with the bill of the baseball cap, but I'm sure it could be detached and used in the umbrella conformation.
Telescoping individual pieces may have to be employed to increase the umbrella's radius.-- daseva, May 18 2011 A baseball cap http://ecx.images-a...s/I/4149H3DZYPL.jpgWhat to do about that damned bill... [daseva, May 18 2011] An umbrella hat http://4.bp.blogspo...BUmbrella%2BHat.jpgThis guy LOVES umbrella hats. [daseva, May 18 2011] If the guy in the link "LOVES umbrella hats", why does he look so completely unpositive about having to wear one?-- MaxwellBuchanan, May 18 2011 Oh, I dunno, I saw it as more as a 'now that I have my beloved umbrella hat on I can stare anyone down with confidence' type look.-- daseva, May 18 2011 hats are a nuisance to wear as is, add all that paraphernalia and you've got a cage on your head.
how about nylon reeds such as those used to hold up a tent. loosen the flexible reeds from their clasp in the middle of the cap and they deploy like an umbrella.-- dentworth, May 18 2011 I was so hoping for a clamshell hat that would open up into a visor. Such a thing must exist.-- tatterdemalion, May 18 2011 random, halfbakery