I am not offended, iPod are IMHO overpriced but also don't automatically join the iPod bashing crowd either no matter how fashionable that might be. A black sheep is still a sheep. Depending on your requirements it can be the only option.
If you are happy to have the MP3 player complety seperate from your headunit then the FM transmittor option on a better priced MP3 player is good option. We did somthing like this for a 3 week trip round Tassie. What I found annoying is that everytime we stopped I would have to manually stop the MP3 player, and then manually restart it again when we took off. Also there was a cable running from the glove box to cigarette lighter socket which kept getting in the way of the drinks holder.
So as I am getting ready for the 3 week trip to Darwin I have put in a Pioneer DEH-P59501B ($370). This comes with an iPod connector at the rear and a cable that you run to the glove box. You then control the iPod via the head unit. When you turn off the car it turns off the iPod and then it starts again from where it left off. You can also select any playlists, albums etc via the head unit. The iPod stays in the glove box out of site of would be thieves with no tell tale cable.
The reason iPod is sometimes the only option is because there is a world of 3rd Party products for them that do not exist for others although I am happy to be corrected on this. For example, when I was looking the only head units with could fully integrate with an MP3 player were for iPods. There are many speaker units that are for iPods.
I also bought a Logitech MM50 ($180?) which runs off a built in 12v battery and can be reharged from 12v source. You just slot in the iPod and control it with a remote control so you can keep it under cover while you sit out in the warm sun. The sound quality of these devices vary greatly but the MM50 is quite good and was the only one I found which was based on 12v. It also has an input for any other device that has an earphone jack so I can plug in the AM radio when the cricket is on.
Both the Pioneer and the MM50 keep the iPod charged as well.
I also bought an iPod camera adapter so I can save the photos from the digital camera at the end of each day. Same price as an SD card but with much more memory. If I travelled with a laptop I would not need this.
I have picked up some foam for packing around items and intend to cut some to fit the iPod to protect on corrugated roads etc but it makes sense that hard drive based units are more at risk. I just don't know how big a risk that is.
If you do go with a a hard disk based device (iPod or most other MP3 devices) then you can do backups from your computer to it (not just music). Given the automated backup at the office never works I find this very useful.
Expensive setup but I use the iPod every day for a variety of reasons so I can justify it.
Headunit: $370
iPod: $500
No more whining from the missus whenever I ask her to pop open the glove box and press stop or play: Priceless

