Although your Joomla Backend shows the software version you are using for your site in the top right corner of the Administrator interface, it does not tell you if this is the latest version.
To stay on top of version numbers and new releases you can subscribe to newsletters, RSS feeds, visit joomla.org on a regular basis or just follow us on twitter. We know from experience that in many cases this is just not enough.
Alexis Sotir and Peter Ader from freakedout.de released a small, simple and free solution for you: the Joomla Version Check Plugin! With this plugin you will get a small visual alert as soon as your software is out-of-date: a blinking Joomla-logo.
On mouse over, you'll get a short message stating the latest version of Joomla. On click joomlacode.org will open in a new browser window, where you can download the latest free patch files for Joomla to use for your update.
You can read the details about the status of your Joomla version in the plugin parameters via Extensions > Plugin Manager > System - Joomla Version Check, again including links to joomlacode.org
Free Download
Joomla Version Check Plugin is available for free at club.freakout.de. (You can follow them on twitter @freakyweb)
Check our Free Tutorials to see how to install this plugin in Joomla 1.5. It is just like installing any other extension in Joomla.
Don't forget to enable the plugin after installation...! If you need help with upgrading Joomla or any of its extensions or templates, just Submit a Support Ticket in the Online Helpdesk!
Why wait? 
