Edit: From what I can tell, after installation of Ubuntu - The guest account is already there - are you sure it is enabled? I can access it from the main login screen. Let us know if it isn't there - otherwise, that's the easiest step - make sure it is installed/enabled.
Here's the options that I employ when setting up a "kiosk"
Preface here: Bear in mind that with most Linux based kiosks - you can always "roll-your-own" - but that tends to be more work than most practical applications call for - but it's a great learning experience, and I encourage it ;)
That being said, here's the easier route(s)...
1. Check which version of Ubuntu you're using - 12.04 LTS already has a "guest" account (You should see it from the main login screen after installation)
-- but if it isn't there -- search the package managers for things like:
Guest mode - Ubuntu/Fedora have a guest mode you can install (xguest):
Here's more information for Fedora (Ubuntu's latest version has a built in guest already available - I use it for netbooks, laptops)
Downside is with using the xguest mode, is it restricts (with Fedora/SELinux) a lot of ports, so SSH sessions etc... are blocked.
Upside: Great for security! Allows for most local applications to be run but nothing is saved after logging off. You can specify via cron a scheduled reboot/shutdown and with GDM options, you can have auto login after users log off, essentially wiping the previous session (stored in /tmp)
More info on cron: »www.cyberciti.biz/faq/how-do-i-a···ix-oses/
You can search Google for your distro's autologin (whichever desktop you're using) - but if using Gnome it could be an entry in the /etc/gdm/custom.conf file like this:
2. Webconverger: »webconverger.com/
- stripped down - pretty useful for web only stuff, can't customize (except for $$$)
3. FreeNX + Guest: (NOTE: This one's more complex, but does function as a kiosk (»www.nomachine.com/documents/admin-guide.php
You'll need to research 2X Clients (www.2x.com), The NX Protocol and No Machines (»www.nomachine.com/
) and the open source FreeNX implementation (»freenx.berlios.de/
) - and most importantly, the Ubuntu (or whatever distro you're using) documentation.
I'd only employ the last option if the terminals/kiosk machines are going to be in tough areas (factories, dirty, extreme temps and conditions, theft prone) - you can lose the terminal and nothing outside the hardware is lost, since everything is on the server end.