As old accessories' connectors do not fit on the iPhone4 with bumpers or a case someone should make an adaptor that would fit on the end of a cord (like a car charger or iTrip) and fit into the slimmer iPhone4 opening. Seems simple to make. I would buy a couple!
I found just such an adapter from SendStation....but the current model still doesn't fit the bumper case. I emailed the company, however, and according to the response below it looks like they'll have one soon enough:
Thanks for your interest in SendStation’s line of iPod, iPhone and Mac accessories.
We have absolutely no idea what the Apple engineers had in mind when they've created the Bumper case. The Bumper case breaks with almost any iPod accessory. To overcome this issue, we are working on a revision of the Dock Extender and a Dock Extension Cable too.
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