11:16 p.m. on June 25, 2011 (EDT)
@Robert Rowe
I'm suprised you havent heard of elf pad's. Here's the theory under which it works. Not to many people know, but the breath of an elf is magical and a wonderful thing to behold, it smells all flowery as well. Being magical it has no limit on it's volume. So somone who knew how to catch these silly little creatures teamed up with a slovic pad company and invented a very compressable, very light weight (for all you ULers) pad that only needs one breath of an elf to inflate it. It's like sleeping on a magical bed o feathers. Their slogan is "Elf-Pads, The most magical night of sleep under the stars". When you order one of these pads you also get and elf and elf care instruction booklet with it. As elves don't eat very much a little elf chow goes a long, long way. Also they only drink the clean water of the morning dew so no need to pack extra water, hence, they are very easy to pack along. They also weigh next to nothing. When ordering your pad you may want to get an extra elf as the mouth piece on the pad will on work if an elf blowes it up. As elf's are very hard to catch, once you lose one you'll have to wait till you get back from your trip to order another one. Another added benifit to ordering an exra elf is that if you have two elf's you have a pair and your elf(s) is(are) much less likely to be a whiny little thing(s). Also you'll want to stake them out a bit away form high traffic areas as there are really easy to step on. Also, if you were to step on one then you'd be elfless (if you only had one) and you'll have to scrape it of off the bottom of your boot (it's kinda like stepping on a large banana slug. messy, very, very messy). I recently checked and you can order either sex of elves. There are currently only white elves avaliable, but there will soon be other variaties of elves avaliable as the company is just completeing negotiations with a number of other land owners in differing locals.
@marienbad
If you want to spend alot of money on a pad there are many options, but there are many good deals out there on a used pad. There are tons and tons of used ones out there. My last one (a Thermorest) I just got a month ago at my local Goodwill store for 7$.
I still use my old orange cascade design from years past. They made many different sizes. In my collection of themorest pads I have some that are 20in,24in and even a folding one that measures 50in across for either one person of very lagre girth or two reg size people, I believe they also made one that was 19in wide. Length wise mine measure 76in,72in and 42in. I find the 3/4 or 42in one to be rather uncomfortable. I know they made some that were 66in long as well. The old thermarest's can be patched with a regular bike tube patching kit, so as long as you dont blow a seam it cost $2 to patch. One of mine has two bike patches. Here is one one ebay that is currently at $9 with no bids with one day left. It is a 20x40 or what again is called the 3/4 pad.
http://cgi.ebay.com/THERM-A-REST-INFLATABLE-SLEEPING-PAD-METAL-NOZZLE-NICE-/260806749584?pt=LH_DefaultDomain_0&hash=item3cb94b2d90
Here is a 20inx66in (my choice)
http://cgi.ebay.com/Thermarest-Orange-Inflatable-Sleeping-Pad-/270769837739?pt=LH_DefaultDomain_0&hash=item3f0b23d6ab
I just checked out a silly little pad called a Z-rest and was going to try it out on my last trip until I laid down on it. It was awful, at least for me. This is one item I wouldn't use even if someone gave it to me for free. I never would have gotten to(any) sleep. These weigh a little more than the new ones but as you will be backpacking across country I think you would be very happy with one of these pads and there are alot of them on Ebay. Check your local Goodwill type stores and craigslist as well. Also this is what I used when I backpacked/biked across Europe
Here's is a themorest prolite at $20 with 3 days left. This is a newer model than the ones I have.
http://cgi.ebay.com/Thermarest-Orange-Inflatable-Sleeping-Pad-/270769837739?pt=LH_DefaultDomain_0&hash=item3f0b23d6ab
I think you will find used pads much more afforable than most of the above new pads, esp. the Elf pad which is quite expensive but well worth it.