I doubt an adapter will work, but please post back if you find otherwise.
I liked the design of a specific dock, but it was labeled only for iPod and iPhone. The sales guy said others had successfully used it with iPad, but when I got home and plugged it in, it didn't recognize my iPad (it recognized both my iPhone and iPod touch, though). I don't know if it's software/firmware incompatibility, or the electrical draw needed for an iPad vs. iPhone and touch. I ended up returning the dock and trying another of the same model in the store, which also didn't work with my iPad.
