I had never heard of Lemi Shine until reading the initial post. Got some at Walmart yesterday and tried it out around our kitchen faucet -- an area that had accumulated a lot of hard water spots. The stuff is A M A Z I N G! Just be careful how you use it. I read the reviews on Amazon, and Lemi Shine will ruin enameled pots if you run them through the dishwasher with it. I'm thinking it would work great on shower doors that are all gummed up, but don't have one here to try it on.
THANK YOU for posting about this product! I would have never found it on my own.