I was reading about contact forms at wpengineer and the code included the wp_enqueue_script call right in the template before the get_header() call. Brilliant! I had never read that about that technique. You don’t have to write conditional statements nor hook in within the functions.php file. This is especially handy if you use a premium theme. Premium themes usually have a functions.php file that includes a huge caveat not to modify it (for a lot of good reasons). An even better benefit to modifying the template is as your theme is updated, you don’t have to worry about carrying over custom edits.