havent seen any for htc devices but then they change much more in forms and sizes then ipods do
one option would be the expansys cable which have both 3.5mm out and usb in then it can be charged and play using audio out at the same time
companys see market and sales %'s and various htc phones is a much much smaler market then ipods
not saying that there is no product like the one you are looking for
but not anything i ever come across
hhhmm ok i may be a jerk but i'm a jedi jerk like my father was before me
BTW "I can't use a skeleton arm with that"