Replying to TV whizzes: Composite->Component/HDMI cables, do they exist?

Just got a new TV, it has one component input and lots of HDMI inputs, but being oldschool we still have a DVD player, a VHS player, and a Wii all with composite inputs. Just wondering if there are Composite-to-Component or Composite-to-HDMI cables/converters out there. Searching on Best Buy/Future Shop doesn't really yield any results, other than standard composite/component/HDMI cables. I've tried plugging in the Yellow composite into the Yellow component input, but I just get a really interlaced looking black and white image. Sound input works fine.