I don't loan out any of my guns unless I'm present. Has nothing to do with what the law says. Here's my reasoning:
1. Most of the time, it's people who have very little to no experience with guns that want to borrow a gun - those are the last people I want to loan a gun to. They really need to rent the gun at a range that is equiped to deal with non-gun owners or they need to purchase a gun and own the responsiblity that comes along with it.
2. My guns are generally expensive and are not insured. If they get lost, dinged, scratched, or damaged, and the borrower doesn't voluntarily pay whatever it takes to make it right, I lost not only a gun, but also a friend. Some have suffered minor dings and scratches when I lend them to someone who is shooting right beside me - at least I can control that a little.
3. If someone wants a gun, then all they need to do is buy one. There are good rifles that can be purchased in the $100 range and good used pistols that can be purchased in the $300 range. If they can afford a cheap lawnmower and a weed eater, they can afford to buy their own gun. Plus, Gunowners only increase in numbers when someone goes out and buys a gun for the first time.
4. There are just some things a man doesn't lend out to others: underwear, his boots, his motorcycle, his wife and his guns.