There's been a lot of misunderstanding as to why it's not possible to "extend" the height of 2 sidebars (when you're using 2) to 1.) match the content and 2.) to appear to be of equal length.
A min-height setting only works if it's pre-established how long all pages will be.
I haven't come across elegant solutions and I'm certainly not willing to go with the so-called "faux-column" idea described here:
This is nonsense because it goes against the dynamism of cms and css capabilities. There has to be another way.
And then, the pending question, where oh where in the template files would it be inserted? In the sidebar template?