Wildattorney-
I use Belkin's Slim-Fit Case. It fits great in my pocket. No issues taking it in and out of my pocket hundreds of times throughout the day; yet, there are a few minor issues. The first being there are times when it is rather difficult to get the iPhone out of the case. I have found that it is better to "dump" the iPhone into one's hand rather than trying to pull it out of the case. If one has butterfingers, I do not recommend this technique. Another issue is to ALWAYS make sure, if one is holding the case and swinging one's arm (like most people do while walking), to hold the case's opening up with a finger hooked over the top. Even though it is difficult to pull the iPhone out of the case, it can and will fly out on its own. The final issue is that the case tends to leave its fingerprint on the screen.
One advantage Belkin's case does have is that its bottom is a screen which allows one to hear your iPhone better, especially when it is in the case upright , not to mention when it's in one's pocket. The other "slim-fit" cases do not have this feature, so I assume the iPhone would have to be placed in the case upside down in order to hear it?
I also use Griffin's Streamline Armband for when I go to the gym. This is excellent. While I'm using the treadmill, I hook the strap on my thumb (I hold on to the treadmill's console - else I'll fly off. 🙂 ) which places the iPhone into landscape mode to watch videos. Then while I'm strength training it goes on my arm for music.
I hope this helps.
joy...suzanne