Basically the title. If you're unfamiliar with CES it's
The Community Exchange System (CES) is a community-based trading and exchange network that enables people and groups to trade their goods and services, both locally and across the world. It can be described as a global complementary economy that operates without money in the conventional sense.
It's also known as time bank and mutual credit system. There are slight variations in the systems (as in, they can be set up however the users decide) but it's basically like I fix your bike and you give me a Time Dollar (that you generated via my work to give to me) and then Alice is offering piano lessons for 1/2 Time Dollar for half hour lessons so I take my Time Dollar and get 2 piano lessons from Alice, and Alice needs a sweater and Bob knits sweaters so she goes to Bob with the Time Dollar and....
It's like that but multiplied by many people and can be distributed further than local area if you find someone to trade with, say like translation services online (e.g. 1 document translation via email exchanges for 2 Time Dollars).
The CES system is getting a complete overhaul btw with open source software and a shiny new UI, so excited for that.
I'm very interested in how others do it so please share if you've got something.