Last weekend I tried using a 12.5 x 20 Aloksak as a pillow and it worked very well.

Did you blow it up with air?

Hmm...I bet you could add some clothes etc inside the aloksak and only have it 1/2 full of air so that feels less like sleeping on a ziplock bag.

I've used both Aloksaks and 2 Liter Platys as pillows. It's a good way to stay light but I now use a 3 ounce Exped pillow. Tad more comfy ;)

The Montbell pillow is the most comfortable. The shape and texture is better, it has tie points and it is very light.

I use elastic straps to hold mine on my sleeping pad so it stays in place.

Other options require that you readjust the pillow during the night.

Did you use some sort of cover?

I've been using a Buff as a pillow case for my platy and it works well. It doesn't add any warmth (that I can tell) but it changes the texture so you aren't laying on plastic. It absorbs some moisture too so I haven't noticed any clammy feeling.

make sure you guys that are using your platy's and such for pillows are washing off your faces before bed. you don't want deet (if you use it) rubbing off your face and onto your water bladder. i would think over time i'd cause some problems... just speculating...