Chrss is a simple correspondence chess service, where the moves are delivered via an rss feed. You can subscribe to your chess games like a blog - whenever your opponents move your rss reader will tell you.
You can subscribe to your moves with any rss reader (Google Reader, Bloglines etc.) or if you'd prefer you can use chrss as a "chess by email" website and get your moves sent to your email address. There are also HTML and OS X dashboard widgets available to track your games.
Unlike a lot of other chess sites, chrss is not a competitive site. You won't find leader boards or rankings. It's just a simple way to play chess online with friends.
As chrss was designed for correspondence chess you can move as slowly as you want. This makes it easy to play a game of chess over the course of a few weeks and not have to rush into a move until you've had time to think about it.
Oh and it's free to sign-up.
Please note at the moment chrss should be considered as being in alpha.