All those things you have sitting around, that you hardly use, or a machine that you have in the garage, can now be lent out to your friends. Some things cannot be lent out without you, like your best chainsaw, so maybe you come with the deal. Some things cannot be moved like a wood thicknesser in your garage, so your help would also be part of the deal.
You can even just lend out your time. Select all your friends or just pick the ones who return your stuff. Instead of asking for cash you can use the internationally recognised currency of a "Cold One"
Also when your friends contact you on Facebook to borrow something you have a record of who borrowed it in your message inbox. You never have to try and remember who borrowed your copy of War and Peace.
Our definition of a "Cold One": A cold or room temperature beverage as negotiated by the parties involved.