This is just a quick note, and there is hopefully more coming on this topic. A friend of mine was able to order his second Raspberry Pi and was so kind to sell it to me. Now it is up and running, updating itself currently. I figured that (at least with the Arch linux image) a screen and keyboard is not needed, it leases the IP address automatically and starts sshd. So just plug it in and connect it to the network and you can ssh on it. Here is a picture, just to make you jealous.