Well, I am not selling the converters yet, I haven't even made the first one.
As far as the firewire goes, both NJB3 and ZEN are avaliable with firewire and USB, and there is a ZEN avalbile with USB 2.0.
I saw the thing about the new I-Pods, and they look nice. The only thing is I-Pods use custom made 1.8" HDD, while the NJB3 and ZEN's use standard 2.5" HDD, which can be upgraded to 60GB fairly cheaply. I am shure Creative and RIO will come out with new Jukeboxes, but it may be a while. Creative plans to make one that plays video, etc. Some microsoft thing.
With connecting to a mac, I'd get an I-Pod. It integrates perfectly with I-Tunes. I don't know if the creative products even work with macs. I don't like apple's OS or hardware (only 1 manuf.), but the graphics are great. I would get an apple just to do video editing if I had a digital video camera.
I think the NJB3/ZEN has better sound than the I-Pod. I have heard both, and the I-Pod is like your typical CD-Player, it has fairly high bass. The NJB3/ZEN has a more natural sound, not as high bass. Which one is better is a personal prefrence, so you just need to hear both. Make shure you have some good headphones though.
The I-Pod navigates easily for anyone, even a 3 year old. The NJB3/ZEN takes some time to get used to, but in about 10 to 20 min, most people get used to it. Some like one more than the other, but I think they are both about the same.
One big thing with the ZEN/NJB3 is that you can create a playlist on the fly, which you can't do with the I-Pod. Depending on which way you listen to music, one can be better than the other. If you like to listen to songs from different artists in a specific order, the NJB3/ZEN is better, but if you want to shuffle all the songs by one artist, the I-Pod is better. It is again, a matter of personal prefrence.
With looks, the NJB3 is pretty much out. They both look nice, but, again, which one looks better is up to you. I think the I-Pods look too polished, and the ZEN looks like a chrome/techno kind of thing. They both look nice, some like the I-Pod and some like the ZEN.
The ZEN/NJB3 does have third-party software better than Playcenter or I-Tunes, Notmad Explorer. It is $25, but it is worth it. Works almost like an external HDD.
The I-Pod and ZEN/NJB3 are different, and you need to figure out which one you like better If you know someone that has either one, ask them if you can play with it for a while. Or ask about the return policy at your local Best Buy or Circuit City. I did have an I-Pod (10GB, run on windows), and I liked it. I did switch to the NJB3, simply because it had recording features, which I use alot. Which ever one you get, you will be happy.