8. A computer program product, the computer program product including a computer readable medium, wherein the computer readable medium is not a signal, the computer program product comprising computer program instructions that, when executed, cause a first computing device to carry out the steps of: identifying a candidate application to be installed on a first computing device; identifying a trusted user that a user of the first computing device has identified and indicated as being trusted; receiving from a second computing device, an indication of installation activity of said candidate application by said trusted user on said second computing device; and determining whether to install the candidate application on the first computing device in dependence upon the indication of installation activity.
8. A computer program product, the computer program product including a computer readable medium, wherein the computer readable medium is not a signal, the computer program product comprising computer program instructions that, when executed, cause a first computing device to carry out the steps of: identifying a candidate application to be installed on a first computing device; identifying a trusted user that a user of the first computing device has identified and indicated as being trusted; receiving from a second computing device, an indication of installation activity of said candidate application by said trusted user on said second computing device; and determining whether to install the candidate application on the first computing device in dependence upon the indication of installation activity. 11. The computer program product of claim 8 wherein identifying the trusted user includes identifying types of installation activity associated with each trusted user.