Dont buy the iTrip accessory for the iPod. I did and the quality is not as good as I had hoped. Mine is having some sort of grounding issue. It likes to use me as an antenna. As soon as I let go of it the sound gets very fuzzy. As long as I'm holding my iPod the quality really isn't that bad but who wants to hold an iPod all the time.
I went to Circuit City and Best Buy. There were two HU that I found. JVC is making a unit for around $179 that has an aux mp3 jack right on front of the face plate. You would just plug into it from your headphone jack on the iPod then switch to AUX mode on the HU. Sony has an Xplod with the solid plack face that flips down to give you all the controls. It's input connection is in the back. That one is selling at BB for $190 and at CC for $230. The Sony looks better but they're both equally equipped. I would probably prefer my jack in the front.
FYI