If you need a headphone amp, Audio Technica has a special one just for you. The AT-HA35i amp includes a D/A converter that supports 192 kHz/24bit audio, along with a max output of 440mWx2, 20-20kHz frequency response and support for 32kHz, 44.1kHz, 48kHz sampling.
But what makes this one unique is that it has a built-in iPod dock. Pretty cool no? It even packs in RCA, S-Video, and digital audio outputs in back to connect it to your other devices. Obviously it will cost you. Expect to pay about $560 when it arrives in Japan next month.