There have been a couple of good threads about this. My recommendation is rubbing in baking soda paste. Here are some threads with other suggestions:
Good luck, Barbara
If I used peanut butter I would have dog lick marks all over them. Its bad enough that when we use lemon oil that he licks that stuff. He would go crazy with peanut butter.
In any case. Cornstarch instead of baking soda works well also. The cornstarch is a finer powder and less likely to scratch the surface. This also can be used to polish Corian counter tops to bring the shine back into them.
I read ( I think it was on Bob Villas website) that you take a cloth (wash cloth or towel) and place an iron on steam setting, place over white ring and let sit until the ring is gone, I haven't tried it yet, but according to what i read, it works
mix cigarette ashes and spit
Tried and true:
Use Colgate tooth paste, or try Steve G. way they work.
Thank you all for the wonderful responses, the baking soda worked, no more ring.
Hooray. That's good to hear. It has worked for me, too, but it was on a natural finish, so I wasn't sure how it would work on fancier finishes.