DVD recorders

Does anyone know if you can record over a tv program or other video file on a DVD disc using a DVD recorder similar to what a VCR can do with a tape? In other words, you record a program with your DVD recorder, you watch the program, then you don't need it any longer so you want to re-record over the same part of that DVD disc. Anyone an expert on this out there?
You can buy DVD-RW discs that can be erased and recorded on over and over. It's easier to use a DVR such as Tivo thar records to harddisk.
use DVD-RW disc to record programs.
Why not simply get a dvd recorder with a hard drive, such as Sony's RDR-HX900. It has a 160GB hard drive, record what you want, delete what you want, and only record to disc the stuff you want. Great machines!
Thanks for the feedback. What I'm trying to do is evalute a DVD recorder that also plays music from live concerts better than average. I'm looking for the best of both worlds, recorder PLUS higher end audio performance. Thanks again.
Are the DVD RW disc's the same as CDRW's in that they sometimes can only play on the unit of origin? Many CDRW disc will only play on the computer they are burned on.
A DVD recorder that records to DVD-RAM. A RAM DVD can be rerecorded on 1000 times. This is about 10 times more then a DVD-RW or DVD+RW.
I hate the Tiem Warner but must say I am really digging the new cable box I have with a hard drive in it.Guess it's same as Tivo in many respects.I am going to get a DVD-R that allows me to use outputs of the he Hrad disc cable box to make a DVD-R.Might install a tuner card in my computer (which I don't really need now) but this would also be option latter if I trade back down from box which cos $7 a month (the only bummer of it).So you can use DVD-RW and re-record but Hard Disc based systems are easier in that you can use them a say a 50hr (or what ever capacity) which is good if say you want more than 74 miutes.If you get a non-HD disc you should have a Cable box with HDF or Tivo since you could leave for a week and record all the news you like,a dozen movies etc hen if it's something you want to keep you dump it onto DVD Recorder or computer with $100 TV card and it's RCA inputs.