dry pack uses

35L is quite a big dry sack, but you could still maybe use it as a pillow case.

I really like drysacks in general for pillow cases because you can roll them to the correct volume to suit whatever amount of stuffing you have on hand. I find this makes a better pillow case than cinch top stuff sacks where you wind up with a pillow that is too soft usually because you don't have enough stuff to fill it fully.

I use a 10L dry sack to hold my down sleeping bag and then when the sleeping bag is unpacked I stuff whatever clothes I have on hand into the dry sack. I roll it to the right size so the pillow isn't too soft and I'm good to go.

As an added bonus, smells don't really get through the dry sack material so you can use dirty old socks & undies in your pillow if you're short on stuff to jam in there. I usually stuff pretty much everything inside for my pillow. I use socks, underwear, tent stuff sack, sleeping pad stuff sack etc….it all goes in and this gives me the best pillow plus it keeps my stuff organized in one spot.

I use one of the 'storm sacks' by SealLine which is their lightest model. A 10L bag is 77g. I could probably get away with a 5L one (62g) but it's easier to get a sleeping bag in the 10L one. I consider a drysack pretty much mandatory when using a down sleeping bag. The extra ounce or so is well worth knowing your sleeping bag is gonna be dry for sure. Otherwise a slip into a stream could ruin your trip…especially if it's raining the whole trip so you have no chance to dry your wet bag.

Another idea is you could use it under your feet if you use a 3/4 length sleeping pad. Just let a bit of air in so it's the right thickness and you're good to go. Perhaps this is what you meant when you said you could use it as a sleeping pad. If you meant using it as a torso sized pad….well maybe but it would likely feel like sleeping on a balloon and your torso weight might damage it.

Another idea is that instead of stuffing your drysack with clothes and rolling it to the ideal volume, you could just use air to make an air pillow. I tried this with two of my dry sacks. One of them (a super light one) would hiss out air from the roll top when the pressure of my head was on it, but my slightly heavier SealLine (77g for 10L sack) Storm sack seems to be air tight. The pillow did want to roll around a bit, but the comfort seemed to be good. You'd want a larger dry sack for this, as a small one (ie. 5L) feels like resting your head on a ball, whereas a larger one (ie. a longer one) does not. 10L is a good size.

I prefer to stuff mine with clothes, but on a cold night where you are wearing all your clothes this is a decent option.

Wash your clothes with it. A bit of Bronners and 10 minutes of shaking should do a decent job. You might have to do this inside out if you want to keep the bag completely dry.

I like the idea of using a dry bag for washing… can't believe it never occured to me.

I know this is a backpacking forum, but this is a biking tip. Hope you don't mind.

How about using it as an improvised behind the bike seat super-twinkie.
http://www.flickr.com/photos/mmeiser2/3656893283/

Works great because it can be set to any size to accomidate your gear and stuffed full to keep the bag taught and stiff.

I was just watching on tv Egyptians using a pig bladder inflated to make cheese with. Possibly disgusting based on cleanliness factors, but how cool would some moutain goat cheese be! :)

Here is an interesting article on dry bags.
http://jwbasecamp.com/Articles/DryGear/index.html

I use Camp Inn Bags when using my Gearskin Pack. They are a bit thicker than the lighter nylon Sea to Summit, but lighter, I think, than the thicker nylon models.
The tinner (Green) Sea to Summit is on top holding a sleeping bag, the heavier Camp Inn is on the bottom holding clothes. Yellow with black bottom. Both can hold water for washing. They dry out quickly. With a full length pad I do not need a pilow, but Sea to Summit is more comfortable as a pillow cover.