Greeters:

Should Walmart greeters get tips? If baristas at Starbucks get tips, why shouldn't Walmart greeters be treated the same?  If you go to Subway, there is usually a tip jar by the cash register. Even greeters in Second Life get tips. If you have ever been to Franks in Second Life, there's a greeter at the entrance standing behind a podium that has a tip jar on it.  

Tips would probably improve service tremendously by Walmart greeters. Instead of you being required to wipe the handle of your shopping cart, a greeter would probably get a cart and wipe the handle for you. They could wear white gloves and dress a little nicer.

The only question is, where should they keep the tip jar? The best way would be to put a small table just inside the entrance with a tip jar on it so that everyone would see it as they walked in.