Rosewill RX353S enclosure using a Seagate 7200.10 ST3500630AS 500GB HD w/ 16MB Cache. I added it to the database.
I've noticed some people didn't get it to work. I did, but only after many tries. The first time I tried, it crashed the whole PVR with an ERROR and it counted down from 255 to 0 in binary, it was quite scary. I hard booted it and it came back to life.
Here's the trick to getting this drive to work:
This drive comes in SATA-I mode with a jumper to limit the speed to 1.5 MBps. Remove the jumper, then connect it to your PC and initialize (not format) the drive.
Then you can hard-boot the PVR with the hard drive and it will format, then hard boot again and it recognizes it.
Edit: It worked the first hour or so I used it, but then I started a recording today and the box crashed again. So I've disabled it for now.