TUAW notes that Apple is currently selling refurbished 5 GB first-generation iPods for $129 in its online store. Originally released in October 2001 and only compatible with Macs, the first-generation iPod utilizes Firewire connectivity and a mechanical scroll wheel.
This is the very first iPod model, introduced in 2001. I don't know how they ended up there, or why they're selling them, but they're shipping "within 24 hours" and are available for $129.00. Remember, this is the model with the "scroll wheel," it's not touch sensitive, and you have to physically turn it with your thumb or finger. Note that the image Apple is using on the store is actually for a third-generation iPod, but the product description and model number are for the first-gen. Also, these iPods are refurbished, they're not brand new.
The first-generation iPod model on offer was originally priced at $399 and was later accompanied by a 10 GB model introduced in March 2002. In July 2002, Apple introduced the second-generation "Touch Wheel" iPod in 10 GB and 20 GB capacities, at which time the 5 GB model was revamped into $299 Windows and Mac versions carrying different model numbers from the original. These "new" 5 GB models continued to be offered until the introduction of the third-generation iPod in April 2003.