I agree with mussels. i think it's a hardware feature. If there's no option in the OSD then you're stuck.
For example my plasma has the options for: just scan, zoom, 16:9, 4:3, etc. which allows my to stretch the display to fit the TV if it's at a lower res than my tv natively supports.
Thanks to BradleyKZN for polishing my sig
“oooooooooooh fire!!! and girls...GIRLS and fire!!!!!!! oooooooooooooh *runz around clapping hands together*” -Marineborn