Here's a simple recipe that worked for me. It is quite inspired by the [wiki:AjaxDojoFormSub] example―and from [http://www.b-list.org/weblog/2006/07/31/django-tips-simple-ajax-example-part-1 this tutorial]―except that this  recipe is expected to use python-cjson for receiving JSON data.

My initial objective was to display validation errors without doing a page-refresh, by using JSON
for carrying errors (or whatever else you could possibly imagine) back to the client browser. 

First thing first, lets write the server view, as its really important to make the forms working 
without the use of Javascript:

{{{
import cjson
from django.http import HttpResponse
from django.template import loader, Context

def register(request):
    # Register or reports any (new)form-validation errors using JSON.
    form = ExampleForm(request.POST)
    t = loader.get_template('myform.html')
    if not form.is_valid():
       # Return JSON object containing the errors object.
       if xhr:
          return HttpResponse(cjson.encode(form.errors), mimetype='text/javascript')
       else:
          # vanilla Http response fallback
          return HttpResponse(t.render(Context({'errors' : form.errors }))
    else:
       # Do something when the form has been validated.
       ...    
}}}


We could try to arrange the client code to fit into one, unportable template chunk, however it's 
usually best to split the work in smaller pieces, at least for being nice to the maintainers (You). :-)

So let's move on in writing our own Dojo template, where we will make an abstraction of all our applied
Dojo concepts.

Quite frankly, that part is going straight-forward, as we're only writing HTML:
{{{
<script type="text/javascript">
    djConfig = {
        isDebug:true,
        debugAtAllCosts:false
    };
</script>
<script type="text/javascript" src="/media/js/dojo/dojo.js"></script>
<script type="text/javascript">
    dojo.require("dojo.event.*");       // sophisticated AOP event handling
    dojo.require("dojo.io.*");          // for Ajax requests
    dojo.require("dojo.json");          // serialization to JSON
</script>
<script type="text/javascript" src="/media/js/ajax.js"></script>
}}}   

The ''djConfig.isDebug'' parameter is important for debugging, so you should 
consider setting it to "true" when inspecting you're application with Firebug
or something else. 

Optionally, you can "bake" your own Dojo file, and substract the baked modules 
from the list of required modules above, so we wont load the already compiled 
Dojo modules twice.    
 
Let's push forward and write down the core JS file, for doing AJAX-related things
with our own custom-compiled Dojo module:

[ajax-related things here...]