TonyR - whilst I agree, I think this debate has highlighted one important exception.
I suspect there are a reasonable number of pilots who use their aircraft for business. After all it is a very efficient means of getting from A to B.
Moreover it seems to me not unreasonable for the client to pay the cost of travel.
It seems to me that the cost might arise in two ways. In an employee employer relationship the employee seeks reimbursement from his employer, who in turn recovers the cost as a disbursement from his client. In a proprietor client relationship the proprietor is effectively recovering the cost directly from his client. Whatever the relationship, the pilot is seeking to recover the cost of getting himself to his client.
The other situation that seems to me likely to arise is that in which the pilot is providing transport for his client. For example he and his client together wish to attend a business meeting and the mode of transport of convenience is a light aircraft.
Setting aside for a moment the law in all these scenarios were the transport provided by car we would be happy to pass on the cost to our client.
As FL says we all want to operate within the law but equally I do not see any of these scenarios constituting "looking for loopholes". I have therefore found this debate very interesting in terms of helping to define where the boundaries might be in the scenarios I have outlined.