Wow! You guys are on the ball! Thanks for all the quick replies. I don't know how to make anything, and don't have a sewing machine. However, how hard would it be to find a decent spinnaker tarp, then cut a slit in the middle to use as a pop-goes-the-weasel hole for your head so you can wear it as a poncho? Of course you'd have to reinforce the slit on the sides, and wear a rain hat because you'd have no built-in hood. But, when set up as a tarp, maybe just have a snap or velcro or something to hold the slit closed. Wouldn't that be flippin simple? I love simple.
I'll probably get a gatewood cape. The thing is, I would tend to use this as a rain poncho only in emergencies. And, when I sleep, I tend to sleep under the stars if possible. So, I would sleep in it only in emergencies. This will probably work fine.
For any owners of the cape, I've got some questions. For one, every picture i see has the right-side beak half folded back to make a door. Why won't the left-hand side fold back? i would love to set up the tarp, with two huge front doors open, and only close them up tight if a storm's-a-brewin'. Also, is the only color grey? I like grey, but was just wondering. And finally, would Mr. Ron Moak maybe make me a spinnaker model without the pocket if I was real nice to him and paid him handsomely? And honestly, there just HAS to be a better way to secure the top of the trekking pole than that crazy rainbow octopus thingy. Sorry--it had to be said. :)