I've been looking to do something similar and came across this thread on thesamba recently:

http://www.thesamba.com/vw/forum/viewtopic.php?t=462083

If you look for posts by "davevickery" on page 2 (and elsewhere) of the thread, he details a cheap and simple DIY awning that only needs a 7 foot wide tarp and a couple tent poles with guy lines (or attached to the jack mounts via pvc pipe). Looks like it would attach to the van a couple of inches above the gutter on late-model westys under the pop top canvas mounting strip. Rolls up and stows under the pop top when everything's closed.

On my to-try list, so not sure of the details...

-Reid