A customer of our low-power Hardy Heron computers (www.aleutia.com) was hoping to set them to serve as internet kiosks at an airport in South East Asia.

Idea is to have them locked-down and authentic through a firefox window (captive portal). User buys a scratchcard, enters details, gets 30 minutes internet access, gets logged back out. Would be nice if Pidgin was there too but not essential.

Came across these solutions, but seem overkill:
http://nocat.net/ looks tricky
http://wiki.personaltelco.net/PortalSoftware - trying ZoneCD out in theory we might run a "live session" off our CF cards.
http://www.dijitanix.com/index.php/cucci - $99 and also seems a bit off.

Upside is people get dirt-cheap internet access and we're not charging them for this - just trying to help them out.

All help greatly appreciated!