There is a plantar fascia sock that can be used.
Ask Ludo about it... his details listed below
Mr. Ludo Straetemans Narrabeen Physio & Sports Injury Centre
1455 Pittwater Road
NORTH NARRABEEN, NSW (AUSTRALIA) 2101
p: +61 2 9913 3212
f: +61 2 9913 3212
Otherwise the low-dye taping as suggested above.
Have you also tried rolling with a dowel stick or "toe crawls" exercise??? Toe crawling is where the patient is standing and then uses toe flexion on one foot to advance the foot forward (only cms!) then the other. I give it for 2m in length as a strengthening for the plantar muscles.
Also i have found that one-legged standing on a wobbleboard with the foot in good position is also a good exercise for promoting natural foot arch position.
Hope it helps!