How to configure a Only-Web-Browsing compiter (kiosk mode)?

Hi,

for home automation purposes I want to add a touchpanel PC on my wall that's showing the current state of my smart home. This PC (Atom based) should do nothing else than to show a full screen web browser (Firefox) as fast as possible (including booting as fast as possible) with modern power saving. No window decoration, no menu, nothing, only the web page itself should be displayed. (OK, it would be great if I could blend in an virtual keyboard when needed...)

The base should be any form of Ubunutu (i.e. Kubuntu, Xbunutu, what ever). What flavour should I take?
How do I have to configure such a system?