Yup, I have an Odroid X running Ubuntu (I couldn't find a Debian that was set up to run on it). It's my mail server, apache server, has an outward facing SSH server, and acts as a sensor data logger. It's pushed pretty much as far as it will go, for a little system like that, with a fairly high load average at times.
Recently had a power cut that killed the system, but rather than reinstall I poked around for a few hours until I discovered the bootloader's zImage had been corrupted. Copied another over from the original install image, and away it went.
When I find myself a decent job, I'll dedicate a more powerful system to the task, maybe virtualize a few of the servers.
Fun projects, although there are many head-hit-keyboard moments in setting it up.