There are a few players out there that do it, but not many, as I think it's a copy-protection issue. I'm pretty sure the DVD Forum (or whatever the DVD standard governing body are called) don't allow it. There are a few players on the market that do, for whatever reason. Some can also be hacked (as with region coding) to allow it too.
I'm not sure if it'd be very beneficial to you though. I guess your TV is a x768 res set, so most likely the DVD player would upscale to 720, then the set would have to scale again. Probably better just outputting at 576p and letting the set scale once
I'd only say it'd be worth it if you were buying one of the new breed of upscaling DVD players, but I guess you can't without an HDMI socket. Bummer.