If you have alot of recordings, you can off-load them to a PC using Tivo Desktop or PyTivo and put them back when its time to watch.
Original S1 (Recycle Heaven)
Series 2 (PLS, sold)
TiVo HD (XL, PLS, "652")
Juliet Basic (4XL, PLS)
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!