I suspect that had IE6 dies off a good few years ago, I would already know this new technique as it is not supported in IE6. But I am very much of the opinion that we no longer need to support IE6 perfectly. I do not want to go into detail about browser support, I have spoken often enough about my thoughts on the matter.
But, no more! position:fixed can now be our saviour. Picture the situation where you have a two column layout with your navigation in the left column and content in the right column. You want the left column to have a solid background colour and be 100% in height but leave a 50 pixel space at the top of the column. You might use the following markup:
....a series of links
Now if you apply the following CSS:
You should see things exactly as I described above. The key styles are on the LeftNavigation DIV, the position, top and bottom styles. You should be aware that this is not supported in IE6 but I have found it works in all the browsers I have tried.
If this is also new to you, have a little play - it has certainly brightened my day!