I highly recommend a great article originally in USA Today (see link) and in today's print edition of the Tennessean. The articles are about how today's CEO's, who don't agree on much, substantially agree that you can tell a lot about a person by the way they treat the waiter, hotel maid, mail room clerk, etc... Originally developed by Bill Swanson, CEO of Raytheon in the 1970's, the Waiter Rule is basically this; someone who is nice to you but rude to the waiter is not a nice person. It is sage advice. It is not uncommon for candidates wanting executive positions to be interviewed over dinner, both as a way to get acquainted and to assess how they treat others. I've also seen "the wife variation" whereby you invite both the candidate and spouse to dinner with you and your spouse to assess (1) how the candidate treats the waiters, (2) how they treat their spouse and (3) what your spouse feels about them as people.
Believe me, you can use this anywhere. The rule works well at all positions, so don't rule out taking candidates for entry-level or lower-level positions to lunch, even if its just to Wendy's. Candidates who are rude to the lady working the counter but nice to you will kiss up and kick down once hired, and we don't need any of that.