The Guest devices are on a transparent proxy thus no proxysettings and it works fine, it can do HTTPS filtering as well on that side but only on modern clients and browsers, cannot remember the ins and outs of that one but it does tell you when setting it up on the smoothie :)
We have a "development" guest wireless with smoothwall as a non-transparent proxy server, using SSL logins against AD, clients need to be configured to use a proxy.pac file. Works best with a device that supports tabbed browsing.
To make YouTube work on an iPhone/iPad we needed to add some domain names to a whitelist.
Was asked to join an Android mobile phone to it today though which does not work with a proxy.pac file, and having some trouble making it work with manual proxy settings.
Not sure if this means that we will have to look at a transparent proxy server with one filtering policy suits all approach to provide a system that works with any device :confused: