MP,

That's the one I was talking about. I can see some multiple uses for that item with a little ingenuity?

If nothing else it would make a good emergency type blanket/ warm weather "sleeping rig"

I'm sure you could use Velcro/snaps to secure in hammock somehow?

That looks interesting.  Would make aready made under blanket.
This is the link that I got
http://www.brigadeqm.com/cgi-bin/tame.exe/store/level4c.tam?M5COPY.ctx=25995&M5.ctx=25995  
Thanks.  

MP, I just clicked on the link, and it loaded for me

In any case, go to Brigade Quarter Masters.
Your looking for their Thinsulate Poncho liner, about 82" x 59", made out of lightweight rip-stop. Looks like you could do a lot with it?

ST
Your link did not work
DD
I copied down the names of the products I will go shopping.  Just my kind of store NOT!
MagicPaddler

This weekend, I accompanied my wife to Bed, Bath and Beyond.  (NO!  I don't usually go by myself!!!   )

While waiting on her to complete her shopping, I noticed a "sheet hugger" product with clips at each end.  I'm wondering if these might work for you.

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dd

MP,

I bet you could use something like this for your needs?
Secure with Velcro/Snaps etc.

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I have a Hennessy with the "factory" insulation system but intend to replace the foam with a military poncho liner which I expect will work as good if not better and compress smaller

Another thought...kayaks come wrapped in industrial strength bubble wrap when shipped to the dealer.  Once off the kayak the piece is 8-12 feet wide and 12-18 feet long.  That's a lot of bubble wrap to play with.  You might find a dealer who will save you a piece of it.   

Lots of good ideas!
Marlin
I would miss the wonders of a hammock.
IC
I think a under quilt of that size would cover the spot.   I have thought about adding clips like clothes  pins to the corners and clipping it on.  To work best it needs to fit close near the edges and loose in the middle.
ST and OS
If  the space blanket were used like IC under blanket it probably would work well.  Humidity goes up and if this is under you I don’t think there would be the condensate problem that you get with it over top of you.  One time when I wrapped the top tarp under the hammock I wrapped it up a little to tight and got that clammy wet feeling.  The space blanket would be light.

I found some 1/8 inch packing foam. When the weather warms up a bit I am going to try it in between the two bottoms.
MagicPaddler

The problem with using aluminized space blankets is that they don't breathe. I tried this once on a canoe trip. I thought I would drown in my own sweat...takes wet-footing to a whole new level.