This is an amazing package for joomla 1.5 and wordpress 3.0 using the beta version. I have been searching for a long time for something as simple as this to show the latest post from wordpress into joomla. I am so happy to have come across this site clickroutes. They have done a wonderful job in developing this module for joomla and plugin for wordpress. If it helps you drop a line on their site to show some appreciation for their great effort and hard work. By the way it is FREE 
It is so simple to set up that it is hard to believe. However not everyone will have the same experience I did setting it up.
I have changed the code to make it work with Joomla 1.7. The code below will illustrate the changes.
////////////////////////// joomla 1.5 format /////////////////////
<params>
<param name=”cache” type=”radio” default=”0″ label=”Enable Cache” description=”Select whether to cache the content of this module”>
<option value=”0″>No</option>
<option value=”1″>Yes</option>
</param>
<param name=”j_blog_url” type=”text” default=”" label=”Blog URL (http://host/path/)” description=”Blog URL (http://somehost/path/)” />
<param name=”j_num_posts” type=”text” default=”" label=”Number of Posts” description=”Number of Latest Posts” />
<param name=”j_num_words” type=”text” default=”" label=”Number of Words” description=”" />
</params>
</install>
////////////////// modified for joomla 1.6 and joomla 1.7 /////////////////////
<config>
<fields name=”params”>
<fieldset name=”basic”>
<field name=”cache” type=”radio” default=”0″ label=”Enable Cache” description=”Select whether to cache the content of this module”>
<option value=”0″>No</option>
<option value=”1″>Yes</option>
</field>
<field name=”j_blog_url” type=”text” default=”" label=”Blog URL (http://host/path/)” description=”Blog URL (http://somehost/path/)” />
<field name=”j_num_posts” type=”text” default=”" label=”Number of Posts” description=”Number of Latest Posts” />
<field name=”j_num_words” type=”text” default=”" label=”Number of Words” description=”" />
</fieldset>
</fields>
</config>
</extension>
If you have any problems setting it up just drop a line here.