What my brother "doneall" means by he has a friend who knows a guy, he means me. I am the one who makes these custom docking stations.
I am an engineer and the production manager for a manufacturing company. I developed it after I upgraded my 2G iPhone to the 3GS and wanted to dock it while in a case. But I couldn't find anything anywhere, so I made my own. And I figured there must be other people in the same situation.
The base is machined from solid aluminum and has a standard sync cable pressed inside. The cable is 36" long.
Your phone is guaranteed to fit. If it doesn't, I will give you a full refund. If your not sure which pocket size you need, you can tell me what case you have and I will make sure you get the correct fit. The standard slim has been tested on the ifrogz (as seen in the pics), Seidio Innocase, and Incase Slider Case. They all fit great.
And no, it doesn't really work well if you want to use the speakers. It doesn't dampen the volume much, but it will muffle the sound quality. If playing music while docked is important to you, you are probably better off with the Sendstation Dock Extender in conjunction with an Apple docking station.
I'm currently working on a black anodized model and one made from solid oak.