My two-year-old twin nieces helped me find this great hint: Huggies bath mitts make great face (and body) cleansers for big girls.

They come with gentle soap already on them and have a great rough texture that's perfect for exfoliating. I'm going to be travelling with these from now on...no more liquid soap spills!

They are $4 for ten, so while they are not exactly cheap-cheap, they are better than the slightly cheaper facial cleansing cloths made expressly for that purpose -- since they are bigger and have more soap, you can use them all over. You can even re-use them a couple of times if you like.