The Belkin Tune Talk is looking like one alternative to mobile recording. It works with many of the newer iPods and the newest Nano.
Why do I think the Belkin Tune Talk might be better than some other microphone? The recording speakers are big and they're facing away from each other. I'm not an audio technician by any means, but having two recording points sounds to me like you'll be able to get decent stereo sound.
The form-factor is just about perfect for sitting it on a table while speaking, but it's not very suitable for stand-up work.
I suspect that most Biz Podcaster readers record in their homes or offices, but there's a growing market for mobile recording. Many audio players are coming standard with input jacks and the number of microphones built for audio players on the market is going up each day.
I use the internal microphone of my iRiver T10 for the infrequent mobile recording I do. It's suitable, but it's certainlly not great. External mics are the way to go.