Well, you could use a module in your blog to link to the search template for easy access to the template. You could use a different alternate search template for each blog; you'll want to set up their names in the mt.cfg file first though.
Here's what I do -- create a New Module named Search Results and put something like this in the Link To File box: /home/USERNAME/public_html/mt/search_templates/ALTERNATE_NAME.tmpl
Hope that helps get you started

Kristine