The Uswaretech Blog: Using Paypal with Django
A great article on using PayPal within Django. Currently for WhisperGifts I create an encrypted button, however this means the users' end-point is the PayPal website. Using the snippets linked to from this article, the user sees PayPal as a single step and the final end-point is on your own website, giving you more control over the checkout process.
http://uswaretech.com/blog/2008/11/using-paypal-with-django/