Newbie in Asterisk. My Asterisk is running on a Dockstar(similar to sheevaplug with less RAM, paid US$25), Spec: 4 USB ports, Gigabit, 128MB RAM, CPU 1.2GHz, 8GB USB flash.
It uses 5W of power, no fan, warm. Memory usage 80+% with freePBX installed. Now it's running without freepbx. It connects several Obi boxes and Sip soft phones.
Quite satifactory at this point of time. When booting into the system, I always find that my system is up faster than my Monitor respond to detect itself.