I put a post up about this just recently, but it was on the tail end of an old thread. I'm in the process of building a tiny folding dinghy called an Origami. I bought the plans from the same guy Christopher bought his from (Wooden Widget). Wooden Widget has a variety of very clever plans for folding dinghies or ones that you can break apart and nest halves one atop the other. Anyway, the Origami is 6 feet long and about 3 feet wide when open. It folds flat to a depth of about 6 inches so my plan is to keep it stored in the v-berth either layed flat or on edge along a wall (it's only 18 inches from keel to gunwhale). I know this doesn't solve your immediate needs, but it's a good solution if you have the space to build a tiny boat.
For the past few years I've used a small sit-on-top kayak, an Ocean Kayak "Yakboard" as a dinghy that I store on edge on the deck. It's been fun but it has a few drawbacks - one always gets a wet bum which sucks if the water is cold or you want to go to another boat for cocktails and you don't want to be sitting in a puddle. It takes up valuable deck space, and it is no good for carrying stuff around. The folding dinghy I can store below deck, I can stay dry when paddling, and it has a remarkable load capacity well over 300 lbs.
Back to the Yakboard: It's advantages are that it is fairly short at 8', it is shallow so that it is narrow when on edge, and it is very, very stable. It's designed to use as a swim/scuba platform as well as a surf toy, so it is meant to be stable enough to climb back aboard from in the water. This stability also means it's easy to get on and off from Virago - many small kayaks will dump you in a heart beat. It's rotomolded plastic so I can bounce it off the rocks around here and all it does is scuff a bit. I won't tow a dinghy of any sort any distance but for the short hops where I've towed the Yak, it has tracked brilliantly because it has a definite keel and two hard chines. And it is effortless to tow - no loss of boat speed.
Christopher, I'd like to trade notes with you once your Fliptail is built to see how the two boats compare. I bought my plans just before the Fliptail was introduced, but I think I would have chosen the Origami anyway - but I like the Fliptail! I'd be really curious about your end results. I'm at the stage where all the components are cut out and the keel, stem and stern assembly is complete , now I'm getting ready for paint and final assembly. It's been easy to do so far even with my basic woodworking skills and I'm really looking forward to launch day.
Just had some more random thoughts about the Yakboard...another advantage of it is that it is a sealed unit so it has its own buoyancy - it can't get swamped and fill with water on deck. Also, it has a slightly rockered shape so it actually wraps around the forward part of the cabin top quite neatly. And it is shallow enough that the stern end of it jams in between the cabin top and the shrouds - all of this means that I actually lash it to the hand rail on the cabin top, not the stanchions, which I think is more secure. It's not a bad way to go all things considered.