It's an Integral Designs Sil Poncho, yellow as shown here: http://www.basegear.com/integral-designs-sil-poncho.html
It's modified a bit:
* I added a bill to the hood
* I added "arms" ... short tubes sewn to the midpoint of each side,
slightly better arm coverage.
It is 5-6 years old, got a fair amount of use for a couple years, have since switched to a DriDucks jacket and ULA rain wrap.
$35 shipped stateside.