In reply to Oliiver:
I'm currently using two hammocks I made myself.
Both are comfy and I find I sleep better in them than on the floor.
The first one I made was out of cotton canvas style material which cost about £8 in total. its big, and good for out the car camping.
the second and third I've made were a pair of identical hammocks made from some ripstop nylon which was a bit more pricey. the benefit is that these are a lot more packable and lightweight.
for both i generally use a short foam mat under me inside the hammock with a sleeping bag or if I've the space then I'll put an old sleepingbag around the outside of the hammock and have another one inside and forget the mat.
its all about creating air pockets!
look into it and the pro's and con's of different ways of hanging and insulating and find what works for you. and enjoy it!