I wasn’t able to pre-order an iPhone 4 for delivery and ended up standing in the reserve line for one here in Houston instead. However, I was able to pre-order some accessories: a black iPhone 4 Bumper case and a pack of white Universal Dock Adapters. I installed the Bumper and that is when I started to have problems with some cable accessories. I also have an example of not having black Universal Dock Adapters when Apple is shipping black iPhones and not white ones. I thought come on Apple how about some black Universal Dock Adapters — is that to much to ask?!?!?
As you can see from the attached photos there is a significant difference in the thickness and height of the dock end between the two cables. My recommendation is to have at least one of each cable laying around, but hopefully you can make due with the smaller one. The larger one did not fit easily and probably could be forced to fit with a Bumper installed, but I thought that handling it roughly that way would not be a good idea.
While this isn’t a show stopper and not a really big deal. I thought you might like to know about it so you don’t get a surprise when you get your Bumper or you are on the road with the wrong cable!
In regards to the Universal Dock Adapters you will find an example of why I wish Apple shipped these in black at the end of this post. I don’t know why Apple never offers these in black, but I guess it must be easier for them to produce these in white than it is to produce a white iPhone 4. Bummer!