man I love css - there's always a new way to skin a cat. I've historically been pretty non-plussed by positioning objects using the float property, but It's actually pretty awesome.
In building the site I posted a mockup of yesterday, I've taken cues from other BI oriented sites - particularly the BusinessObjects site. They've got 3 columns. I've always had problems with columns, and had to do some funky positioning based on which column is longest - otherwise they run over anything under them, like a footer.
A better solution I saw by checking out their CSS is floats. Each column is a float left. You can then make the footer float left also, and voila - nothing covers up the footer. Even better - you can give all three columns the same class, instead of a special one for the "longest" column - I always hated that - it felt like breaking the spirit of CSS.
Yeah, so if you aren't me, or performing a search on CSS techniques, this is one boring ass blog entry