Which is Optimal

This is my scene.

I have around 1, 000, 000 products in database.
In my front end, user can select products by clicking a button.
once user clicks the button i have to show him all the products from the database, as a popup.
Now to show all 1, 000, 000 products, system hangs, responds after 5 minutes.

How can i show all products without much overhead.
will XML do any good.

Vj