"I use one, I have used one for a long time, I read a bunch of other sites reviews of this question. You are fine with a magnetic case. By the way, I run a Computer Services department for a University. I do spend a lot of time with this stuff. Anyone saying it is bad is just dispatching FUD."
What you are saying is BS! I had two different cases with magnets that drastically messed up my iphone. The two cases were very different. The first one had a large magnet and the second only had a very small magnet. Unfortunately, they caused my iphone to malfunction. Both times, I had a **** of a time getting my wifi to work again. So, I know that magnets can be hazardous to the iphone.
Over the last several years, I have had Sena cases for my pdas. Every one of them had magnetic closure. Not one of my pdas had any problems with the magnets. So, I tried one for my iphone. For over a month, I have used it and have experienced no problems. Apparently, Sena uses a different type of magnet (as mentioned above-neodymium?)that doesn't have the deleterious effects.
On ebay, there are a lot of cases sold that contain magnets. I would bet that a lot don't use the "safe" or at least "safer' magnets. Possibly, this could be why many report malfunctioning iphones.
Make no mistake, certain types of magnets can definitely harm the iphone. At present, my iphone is working great. I will cross my fingers that no long term damage has occurred.