Which iPhone 4 -- 16GB or 32GB ?

I would get a 64GB if I could.

I have the 16 GB original iPhone. My choices were 8 and 16 GB. I chose the 16 GB. I have a variety of apps, music, photos, music videos, and 2-3 movies. My free space ranges from 1GB to around 300 MB. It all depends on how you want to use your phone. My wife doesn't care to have any movies on her iPhone, not much music, not many photos, so 16 GB is plenty of space for her.

I chose the 32 GB iPhone 4 because I knew I could use the extra space. My wife will get the 16GB when they start taking orders on the white model. If you think you will want to carry more than 16 GB of data with you, then get the 32 GB.

I pre-ordered a 16GB but am thinking I should have ordered the 32GB.

Any ideas how I change this without canceling my pre-order?

I did the same -- ordered a 16GB 4G because my 3Gs was 16 and I was OK. I don't need to replace my iPod and if I watch too many movies on a flight, I'll land with no battery. My jury is still out, I ordered the 16 and while waiting in the shipment queue, I had second thoughts. Even my wife said to get the 32.

The only way to flip your order is to cancel the old one and reorder. I did part 1 yesterday and still haven't reordered the 32. I might just save the hundred and re-order the 16. I used to be indecisive but now I'm not so sure.