You can turn it off. I spend a lot of time in Google Reader, so efficiency and lack of distractions is very important to me. I turn off widgets that I don't use in most of the sites that I frequent.

The way you can turn it off it to install the Stylish extension for Firefox (which allows user specified style sheets on a per-site basis), use Firebug to find the div id or class of the widget you don't like, and set it to "display: none !important".

Stylish is similar to greasemonkey, which means that you can usually find someone who's already done what you're looking for, and shared it. Here is my stylesheet to make Google reader minimalistic: http://userstyles.org/styles/12663 and here is what it looks like when installed: http://bit.ly/minimalreader You can temporarily disable it with a single click when you want to use any of the hidden widgets.