I have an iPod dock adapter plate that came with my 2nd Gen iPod Touch. So i altered that to be the dock on top of the can. First i used a file to widen the slot in the bottom to better accommodate my iPod connector. The i used a scrolling bit in my Dremel to cut a space to allow a head phone jack to be mounted.
Next i went about mounting the iPod connector and the headphone jack. The jack i'm using is from the speaker set. (As mentioned before the final product will use a panel mounted jack and a double male cable to connect the speakers to a PC or laptop.) First i set the iPod connector in its slot and set it about 1/16" up from the bottom of the bock plate. I wanted the connector as close to the bottom as possible but still allowing the plate to keep a pinch on it. I then hot glued the corners of the connector to the dock plate. Next i plug an iTouch into the dock and connector. This allowed me to plug in the headphone jack and have it perfectly aligned. I was then able to fill all the gaps with hot glue and make everything nice and secure.