iPhone 4 and Windows Phone - Swappable Sims?

I'm in a unique position in that I purchased an iPhone 4 in the Summer and just recently purchased a Windows Phone 7.  This was made possible by Mr. StevieB, CEO of Microsoft, with his generous offer of buying all employees at Microsoft a Windows Phone.   I felt a pang of loyalty and decided to take the plunge.  I'm sure that most of you out there who are not similarly compensated would never give up on their brand new shiny iPhone 4 for a shiny new AMOLED enabled Samsung Focus but if for some odd reason you are then this might be an article for you.

First off let me explain that my family and I are heavily locked into the Apple FairPlay system which is a digital rights management system from Apple.  Our first iPod was a 2G many years back and we've continued our love affair with the tiny music device with iPod shuffles, Nanos, Touches, iPhones and now iPads.  It's safe to say we have a fair amount of FairPlay content locked up in Apple's very capable licensing DRM technology.  All of which will not play on a Windows Phone.   Also with the Windows Phone being a v1.0 product I wasn't quite sure I was going to love the device enough where I could live without my iPhone.  So I basically wanted to hedge my bets.  The problem is that the iPhone 4 has a the tiny Micro-SIM and every other phone out there uses a Mini-SIM so they aren't swappable.  Problem!!!

Here's what I decided to do.  I purchased an adapter from Amazon for about $3 that converts an iPhone 4 Micro-SIM to a regular phone Mini-SIM.  Basically the adapter is a piece of plastic and the iPhone 4 SIM snaps in making it the size and dimensions of the Window Phone SIM.

I took this to my local AT&T store and asked them to use this hybrid SIM when I purchased the Windows Phone.  The sales guy told me it wouldn't work. I of course squeaky wheeled it and whined and he eventually brought out his manager.  She was very nice and told me that they just couldn't guarantee that the SIM would still work in my iPhone 4.  She also went on to explain that the iPhone has a unique data plan that is different from the Windows Phone and that even if it did work I would lose some features like Visual Voicemail since the Windows Phone didn't have that feature.  I then plopped my iPhone 4 SIM hybrid converter thingy into the Windows Phone and they proceeded to provision it.

The Windows Phone launched and everything worked.  After I brought it home I popped the SIM out of the converter and put it into my iPhone 4 and it also seemed to work.  Now I don't know if AT&T gets some signal that says I've switched and then could in theory turn it off but it worked for the brief time I tried it.

Since I've switched to my Windows Phone permanently I haven't tried it again but my guess is that it still works.  Anyway, I thought I would blog about this since it might be something people were wondering about.  I'm guessing this will be primarily for my fellow Microsofties who are doing similar things or maybe on the slim chance that you are one of those people who are fed up with dropped calls from the iPhone 4.

Anyway happy SIM converting....

12/27/2010 UPDATE:  So far so good.  It's been about a month or so and no issues with this SIM card.

1/31/2011 UPDATE Part 2: Ahh well I just tried it again and I guess the data part of this equation never worked.  The phone worked fine but the data plan didn't.  I think what happened before was that when I tried to do data things I was actually using my Wi Fi network and not the 3G data network.  Now when I try it without the WiFi I get the error message that there is no Cellular Data Network available.  Bummer.