Over at Mac HTPC, they're blogging about the Micronet miniMate, a device that supplements the Mac mini by adding a bigger hard drive and a USB 2.0/FireWire hub. All of this is built into a form factor that apes the mini. From the publicity photos, the combination looks quite nice.
Although, let me make one comment to MicroNet: lose the S-Video-like power plug. I have a couple of FireWire enclosures that have this type of plug for power and they make a terrible connection. What ever happened to the mail socket and female plug that used to be standard in computers?