So, I tried the poncho thing today because I decided on the way to the gym I wanted to shower there and there was a poncho in mt trunk.
IT FREAKING WORKED. I'm not quite sure how we managed to pull it off, but it worked, and it worked very well! Logan stayed completely dry, though he was pretty sad about wearing a poncho and getting in the shower. I just wrote up a longish post in my blog if you're interested, but I'm about to head for bed nwo and don't want to type it all out again
http://theeclecticcollie.blogspot.com/2013/01/where-theres-will-theres-way.html
Anyway, I will be trying other methods, because despite staying dry, Logan wasn't thrilled with the situation (but he held his sit-stay and did not complain, SO proud of him! <3). I don't want to make it a bad experience for him over and over, so I'm leaning towards the popup crate.