When the face wash I used to use started to irritate my skin, I started using olive oil soap.
It’s great for travel, because you can also use it as shampoo. That means two things (facewash or shampoo) I no longer have to worry about squeezing into my TSA-friendly quart-sized bag. Phillip will cut a slice off the end to make a travel-sized bar.
What I haven’t figured out is the best kind of container to pack it in to keep it from getting slimey (like soap does in a plastic baggie) without taking up a lot of space (why do they make travel soap dishes so big??).
P.S. There’s a post on SmarterTravel with some interesting suggestions for packing without liquids. Who knew you could get toothpaste in tablet form?!