Hi,
I don't know if you have ever approached Sophos about making a Portable Apps version of their software.
I can understand that they may not want their full package made as a portable app as you have to register a limited amount of machines against a uer account, but Sophos do make a stand alone Virus Removal Tool, which can be used on any PC at any time and would be great to add to the collection of diagnostics and security tools that are already available on here.
Just a thought.
Cheers,
Barry.