You could use a JSON array as Samet suggested, or even just regular JS variables.
<script type='text/javascript'> some_numeric_property = {{variable1}}; some_string_property = '{{variable2}}'; </script>
Another way to do it (the way I'd usually go) is to pass all the details you need in via function calls and data- attributes. For example, if I wanted a certain link to pop up an AJAX bubble with a user's profile on hover I might do this:
<a href='/profile/{{user.id}}' onmouseover='show_user_popup({{user_id}})'>{{user.name}}</a>
or this (presuming my script was attaching events to links with classes of user-link):
<a href='/profile/{{user.id}}' class='user-link' data-uid='{{user_id}}'>{{user.name}}</a>
You could also call these functions in the head of your HTML straight after loading it if desired.
<script type='text/javascript' src='{{MEDIA_URL}}/js/whatever.js'></script> <script type='text/javascript'> do_something_with_a_number({{variable1}}); do_something_with_a_string('{{variable2}}'); </script>
The advantage of the latter is, because no code gets executed when you load the JS file (with the exception of creating and binding function objects, obviously), you can have the one JS file included on every page on your site, and just call the bits you need on the appropriate pages. This one file would then get cached after the first load (assuming you're sending the right headers), decreasing load times for subsequent pages.
EDIT: security considerations: The method I've described (along with many of the other methods on this page) suggest inserting data as either a) attributes of HTML tags or b) JavaScript entities. This is safe so long as you know the data either a) can't be set by untrusted users or b) is always in a "safe" format (ie the data comes from a SlugField or an IntegerField or something in the database).
However, if neither of those are the case, you'd need to protect against HTML and/or JS injection, by escaping the appropriate characters. Django's default behaviour of HTML entity escaping might protect you in some cases, but it might not, so it's worth checking.