Come scritto su http://wpmudev.org/project/GT-Search-All-Blogs

This is the new version of my plugin. I added more features and it is a little less buggy (I hope). Here the features:

• Search among posts and pages published in your wpmu installation;
• Results are ordered by the most recent to the oldest post/page;
• You can decide how many results you want to show per page;
• It’s easy to translate in your language (the default language in English).

To translate your search engine, open language.inc.php and change the variables from English to your language. If you want, you can send me your translation and it will be available on this page. As usually, please report any bug or error you have. Thanks.

• Installation:

1. Copy gt_search_all_blogs.php and language.inc.php in your mu-plugins directory.
2. Copy search.php in your template directory (overwrite your search.php, or modify your search.php, if you want).
3. Enjoy your search in your WPMU main blog.

P.S.: The last version reached 100 downloads (and it was not so beautiful!).