Unfrozen Caveman Webmaster here with a tip!
When I designed with table-based layout, I designed many layouts with blocks of text vertically centered in a table cell. Piece of cake! Unfortunately, css doesn't seem to provide an easy alternative, although I'm very new to table-free css layout. I have come across two methods (hacks, whatever).
To vertically center a single line, set its line-height to the height of the element you are centering it in.
For blocks of content, today I stumbled across the following solution, which is so elegant and well-presented I thought I'd share it here: