When channel crossing in a S/E aircraft a number of us always have 121.5 already selected on box 2. This is a result of our long discussions of the safest options in the event of an engine failure over the channel. These discussions were prompted by a fellow pilot who used London Info for his MAYDAY and told them where he thought he was. London info does not have radar or the autotriangulation of 121.5. Although uninjured, he was dead by the time he was found.