How to persist data across multiple requests?

The signup process for my app is as follows:

Users click a signup link for a specific plan
They fill out a simple email/password form
After submitting, they are asked to check their email for a verification link
Clicking the verification link takes them straight back into the signup process and they can continue to add payment info etc.

The problem is I'd like to save data from before the email verification step, specifically which plan they clicked so that that is the default setting on the payment form.

I tried storing this data in a session variable (I'm using django.contrib.sessions.middleware.SessionMiddleware), but the session data does not persist into the new tab/windows that opens from the email client. Other than saving this info in a model (which I'd really rather not do for such transient information), is there any way around this problem?

Solution

you can use html 5 feature local storage http://diveintohtml5.info/storage.html