I saw some just the other day. I went for a ride on the SolarSailor (a
hybrid sail / pv-electric / gas turbine-electric 100-seat ferry-boat) on
Sydney harbour (Australia). They have traditional pv array on the boat's
fixed deck surfaces, but the sails have flexible solar array built into the
sail structure. These panels are both flexible, and of a "buried contact"
design meaning no metal strips across the pv cell => higher output. See
either solarsailor.com or solarsailor.com.au (can't remember which).
Yes, has been around.
Amorphous technology, where the silicon is sprayed on thin, flexible
metal sheet, rather than grown.
Not as efficient as christaline silicon.
JS
My company, Global Solar Energy makes "flexible" solar panels that can
be folded to fit in a backpack. Several sizes are available from 5
Watts to 55 Watts. We used to make a rollable panel, but if rolled to
tightly it would be damaged, and it was hard to control how tightly the
customer would roll it. Check www.globalsolar.com