There's a nice leather one from Knomo available for £50, the iPhone wallet. As you'll gather it's a combination phone and wallet so you need only to carry one of the things around with you, which is a step forward for blokes trying not to rumple their suits with too much in their pockets (you know this is a problem when, as happened to me relatively recently, a tailor takes your jacket and complains it's too heavy...or was that my mother, or wife, or all three...).
here (this leads to my Amazon affiliates site, I will get a small amount for every one ordered through this link).
When the review sample arrived (see picture) my initial response was that it was over the top, tacky and definitely not for me. My daughter, on the other hand, thought it was brilliant. "I love cheesy stuff", was her response, and it's certainly not for the understated.
Both are nicely made and would stand up to being pulled out of your pocket a few times. For me there's still a bit of a concern about pulling all of your money out every time your phone goes off, you never know who's watching; I hope I'm being overly cynical about that but in spite of the convenience I'll probably stick with a separate phone and wallet case for the moment.
What do other people use?