Not to hijack the thread, but I have an interesting story about picks and ukuleles.
I had a friend who asked to borrow a ukulele so he could try-before-buying. So I loaned him my Samick concert. It's what I started with, and it's a comfortable instrument. He enjoyed playing, and he wanted to play one during a church service. It was going to be a bit before he could purchase one of his own, so I loaned him my Ovation Applause tenor. It has pickups, so it's easy to use with a PA. When I got there, he was warming up, using a medium gauge pick. I told him I wasn't comfortable with that, but he ignored me and used the pick for the song.
Now, I'm not saying picks are evil or anything like that. It's your choice how you play your own instrument. But if you're going to loan them out, be explicit about how you want others to play your instrument.