I used the Griffin adapter to hook in my IPOD Touch. One MAJOR problem is that I only get audio out of the left speakers when I am using the adapter. It could be my (POS)iPOD since it did this to me while on a plane with my BOSE headphones.
I plug it in for about 20-30 minutes and get enough charge to last me about a week or two (depending on use), then I simply remove the adapter and hook it into the OEM wire. This is probably not an ideal solution for iPhone users since your battery gets depleted a lot faster due to phone use.
When charging it does not unhook and its pretty stylish when compared to other adapters I have seen. I got mine for 10 bux on Amazon, but it seems like its a lot more money now not sure why.
http://www.amazon.com/Griffin-Charge-Co ... roduct_top