An old or not often used computer that a person may use as much as a regular computer, with the exemption of common sense to avoid viruses or any activity in general that may destroy the computer.
A person may use this before throwing out the computer by visiting sights normally advised to avoid due to the virus chance, like strange porn sites or sites offering free things, for the purpose of just seeing what they are like without having to worry whether the computer gets a virus or not.
These computers would be void of any personal or financial information in the very likely case that it catches a dangerous virus.
I really want to visit this site promising me a thousand dollars if I answer what Tom Cruise's birthday is, but I'll probably get a virus.
Don't worry, that's my compikaze, so I don't care if you get virus's on it!