Just a quick update.
Germy, who I linked to in the first of the paper-craft terrain posts, has updated his site very recently. It can be found here: Germy.co.uk. It is nice and easy to navigate, and the 25mm section (most applicable for Pulp City of other modern/near future miniatures games) is neatly laid out under the 'Paper Models' tab. Worth a look and the paper models are free to download for personal use.
Not free but maybe offering an interesting future proposition is Taylor & Smith. They are starting at 15mm and 20mm scales, but when I briefly spoke to them at Salute they made it very clear they are open to suggestions regarding future products.