I think my use of the word 'invite' has been misinterpreted here. It was meant in the sense that, I asked my friends if they would like to come flying with me and share the costs of the plane too. Please note I have been particularly careful to make it clear to my friends that flying would be on a cost sharing basis.
As a fairly skilled mechanic myself, I'm regularly fixing my friends cars. I've spent entire weekends fitting engines and fuel injection systems for custom conversions etc for nothing more than a beer. Since becoming involved with IT, I find much of my spare time is in addition spent fixing friends (and friends of friends) computers, including my friend in question. I've even taught some friends to windsurf for free, exept they had to hire the boards from the school. Never have I asked for payment, or expected anything in return.
Its just that I cant afford to fly them for free too!