As Suntan mentioned, a typical one hour of HD from OTA is between 6 to 7 GB. For example, tonight, my wife just recorded Idol (one hour), it came out to 6.5GB. Edit the commercials out and it will be down to about 4.3GB (about 42 minutes of video). Re-encoding it to h264 and maintaining quality, you can reduce it down to about 1.6GB per hour (about 1.2GB for a 42 minute show) but it will take anywhere from 8 to 12 hours depending on your CPU. Really not worth it with disk storage being so cheap.