iPhone Spinning Wheel of Death Solution

When I woke up this morning, my iPhone 4 was showing a black screen with a round spinning wheel in the center.  Note that no apple symbol was showing, just a totally black screen behind the spinning wheel.



I let it be for about half an hour and then I figured, this can't be right.

I did a bit of research and tried different solutions including holding the home button and the sleep/wake button (top right hand corner) for 60 seconds - to no avail. Another solution included waiting for the battery to die out - with a fully charged unit I was not prepared to go down this path.

Here is the way I resolved the issue:
1. I plugged my iPhone into my computer
2. Opened up iTunes
3. Checked to ensure my iPhone was detected in the iTunes menu on the left

4. I noticed the Capacity indicator at the bottom of iTunes showing only a yellow Other indication.

5. I held down the home button and the sleep/wake button for about 15 seconds and the phone went blank.
6. Once it restarted, iTunes showed the correct Capacity again and the phone was back to normal.

Still no idea why the phone spontaneously crashed like that but I am glad that it is sorted.