jQuery-Tie Demo
Match the width of element A to the width of element B
Match the width of element A to the height of element B
Match the width of element A to twice the height of element B
Passive resizing with a global listener, tie width of A to B
Passive resizing with a proxy listener, tie width of A to B
A is in container B, match A's "left" css attribute to 1/3 B's width