Sure you can charge and sync your iPhone 4 with the plain ol cable, but I’ve always liked the formalness of a dock. I tracked this one down and although it isn’t designed specifically for the iPhone 4, it works pretty well, *even with the case on*. I got it on iOffer and it’s called the “Apple iPhone dock charger Sync Cradle for 4 4G 3G 3GS“. It’s listed for $6.50, but that excludes shipping. You don’t get the shipping cost until the seller contacts you subsequently. Shipping ended up being $8.00, but $14.50 still seemed pretty cheap overall.
The picture in the listing didn’t show the clear plastic backing and bright blue LED light. There is also a small cap that comes on the end of the USB cable. I superglued it to the top of the clear backing to support the back of the thinner iPhone 4. Amazingly, it’s basically the exact thickness that is needed!
The dock acts just like the iPhone cable, so I can charge and sync my iPhone 4 when it’s in the dock. I’m quite happy with the purchase!