I recently got one of these. It seemed to work well, so I ordered a second. Then I realized that when the battery is more than about halfway down, this charger WON'T CHARGE THE iPHONE 3G! The phone claims it is being charged, but it will sit for hours and actually discharge over time. The charger that came with my phone works just fine, even if the battery is nearly dead. I have the same problem with both of the Inspiretech chargers. So I would strongly recommend against buying this charger. I suspect there is a fundamental design defect here. Anyone else have the same problem?
I also have one of their car chargers, which initially seemed to work. I will have to do some experimentation to see if that, too, suffers from the same issue.