I have a potential career adjustment pending, which revolves around setting Asus eeePCs up as conceptual appliances.
The eeePC would have another chunk of Flash for writing stuff like log entries, DNS updates, cache records, maybe email onto, which would conceptually be replaceable in situ by staff. The idea would be to plug in another (USB2 stick-based) chunk of Flash, which gets the structure & basic data from the old writeable Flash copied onto it, then remounted to replace it, allowing the old Flash to be unplugged & (if necessary) snail-mailed to head office.
One immediate “appliance” function would be to act as a VPN, proxy-cache (& filter), DNS secondary, perhaps SMTP sender, & also (potentially alongside the VPN) as an ssh (potentially equals PuTTY) port-forwarder.
An aspect which seemed initially appealing (but the wireless connectivity issues in one client city will probably can this idea) is to deploy it behind a suitable ($85 retail) wireless ADSL router, & use the wireless link to securely forward Internet data to the eeePC, then its built-in Ethernet port to relay that to the clients. In reality, the built-in Ethernet will talk to the router (maximises connectivity to at least the eeePC), & a USB Ethernet interface will talk to the internal switch.
The advantages as an appliance include modularity, easy replaceability (& can be snail-mailed in an Express Post pak plus a layer of bubble-wrap), built-in monitoring (screen) & controls (keyboard, mousepad), built-in Ethernet, replaceable/disposeable/portable storage, ruggedness, size, low power consumption (& brown-out protection, extensible via USB-powered DSL routers), extensibility (3xUSB2 ports, SD Flash socket), & it can come in a cute pink colour.