[jQuery] resize columns!

[Simpel]

Hi there

has anyone seen a demo or something that can resize the width of
several div:s? What I'm looking for can be found on netvibes.com. They
have a nifty little feature(try and drag the little rectangular box
that is situated between the columns!) that let's you resize the 3
columns. I need exactly the same feature for a project....tips/ideas
anyone on how to program this little thingie?