I have lately been inspired by the fonts used on military armour, particularly the text on German WWII vehicles. A quick bit of Google-fu turned up this wonderful collection of .ttf files. It's a pity my favorite, the Blockschrift für Flugzeuge, seems to be very broken (as, indeed, are all other instances of the file across the interwebs). :-(
I also came across a great collection of gothic script fonts used on German tanks, but alas the link has disappeared into the black hole that is my History. Sorry.