[Digital downloadable products] When to intecept completed transactions?

[MrBaseball34]

I am working on a digital download system and have been able to successfully get my PP sandbox mode working.

Now, what I need to do, because our content is to be dynamically generated, is to determine where to insert a record in a new table that will be read by a cron job to generate the product.

Should it be in Paypal.php class's validateOrder() function or in validate.php?

Remember, I'm also going to need this for Google Checkout so maybe it should be in the PaymentModule class's validateOrder() function?

I can also create a trigger on the ps_orders table to do what I need but I am not sure if that's the route we want to take.

When is the order actually created, anyway because I'm going to need some info from the order to generate the download and confirmation for the customer?

[MrBaseball34]

Bumping this topic so maybe I can get an answer from somebody.