Is it proper to tip maids with other than money?

We leave $5 daily, we straighten up the room and bathroom, wipe the sink clean, try not to leave hair anywhere. Pile the used towels/washcloths for pickup in one pile (I know...that's another topic). Have also left some of those vases and other useless promo "gifts", but never instead of cash tip.

Some people don't mind cleaning hotel rooms, houses, etc. as much as one might think. My friend's mom cleaned houses (bathrooms and all) and enjoyed it.

My wife has her hair done by a women who is also in housekeeping at the Venetian. A number of times she has given me Spearmint Rhino tokens to cash in for her, so obviously, these are sometime left as tips. As a Limo driver, I am able to cash these in at Rhino, and I give her the money back. One time she was left $300 in Rhino tokens.

Larry (limo driver) from Las Vegas

Always cash daily with a Thank You note on the nightstand.

What kind of tokens do they Rhino give out. Since I don't go to those places, I would have no idea.