DanCoulter

Once this plugin is activated, you’ll be able to use the new “shortcodes” 
in your sidebar text widget. The shortcodes will work exactly the same 
way as they do in your posts.

Sidebar Shortcodes

Allows shortcodes to be used in the sidebar text widget.

rzvc

It displays random qoutes on your sidebar or on your page depending where you want to be shown.
<h3>Usage</h3>
You can add the quote on your sidebar by using the “Quote” widget that allows you to set the title of your block, number of quotes that you want to be displayed or one specific quote.
You can display the quotes via template by using <code><?php do_action( 'r12themes_quotes' ); ?></code>.
This sintax can be customized by using the following arguments:
<ul>
<li>‘limit’ => 1 (the default value – e.g <code>2</code> will display two random quotes )</li>
<li>‘id’ => 0 ( display random post – e.g. <code>19</code> will display the quote that have id = 19 )</li>
</ul>
You can add this in your post by using [r12themes_quotes], the arguments above apply to this one to.

R12Themes Quotes

It displays random qoutes on your sidebar or on your page depending where you want to be shown.

Sidebar Shortcodes vs R12Themes Quotes