Suggestion Customising the content that appears in the sidebar

[smileyhead]

I like the sidebar. It makes threads with long rows of text look tidier by narrowing the text space.
The amount of information it includes, however, I don't like. This is especially apparent in shorter threads, where the sidebar keeps on going long under the most recent post, resulting the bottom of the page being far-far away, and an ugly empty space between the latest message and the bottom navigation of the page.
I would like to select (and maybe arrange) what content appears in the sidebar, if possible, so it includes less content and stuff I'm actually interested in.