There are times when you’d like to have a certain type of post appear in a widget for use in your sidebar or (in some themes) your header or footer.
I used this to display a random senryu on each page, but it will work equally well for any group of reasonably small posts.
There is the option to include the title of the post, the title of the widget, both titles, or neither.
If you want you can add a bunch of widgets, each showing up to five random posts from a different category.

Random One Cat Widget

This Widget shows up to five random posts from a given category

fred91

Simplicy Random Post The options:
Item number posted 
The month of publication eg December = 12 (Set to 0 to disable this option) 
The year of publication such as 2011 (Set to 0 to disable this option) 
Category selection (left on ALL to show all categories) 
Max number of users has preloaded 
Displaying a thumbnail or not 
Size of the thumbnail 
View a excerpt or not 
Length of the excerpt 
Auto refresh or not 
Setting the refresh interval in seconds
Languages: French / English

Simplicy Random Post

Simplicy Random Post is a WordPress plugin that allows you to display random items in your sidebar, you can choose the month and year of publication o …

Random One Cat Widget vs Simplicy Random Post