Most TV sets actually do support 16:9 enhanced mode. The difficulty is that the control to do it might not be conveniently accessible. It might be a screwdriver adjustment perhaps labeled "height" or "vertical size" under the back cover, or a menu or service menu adjustment perhaps labeled "vsiz".
If the 4:3 TV "officially" has 16:9 enhanced mode, there will be information about that mode in the instruction manual.
If the 4:3 TV has gray instead of black top and bottom bars when in 16:9 mode, (turn the brightness way up after turning the contrast way down, just for a minute) it is probably not giving a true 16:9 enhancement but rather is doing the same downconversion that DVD players use for 4:3-only TV's.
Video hints:
http://members.aol.com/ajaynejr/video.htm
