some days ago I created a new block featuring searches across all the enabled glossaries in a course.
Source code is available under CVS Contrib. I've attached one zip file containing it here too.
To install, just unzip it under the "blocks" dir, go to Admin to enable it. You can configure the format used to display results under "Admin/Configure/Blocks".
It's a quick prototype so any feedback will be really welcome.
Ciao