[jrm01]

You say that your TVhas only one RF input. How about AV inputs (red/white/yellow or s-video). If you have that try this:
http://customersupport.tivo.com/LaunchContent.aspx?CID=691CC48A-CF9B-48BB-BB21-594032E00393

Just substitute the DVD recorder for the VCR in the diagram. Use s-video instead of the yellow if you have it on your TV.