Sometimes you can find old metal letters from vintage signs but it is often hard to find the right letters to spell an actual word. But if you have something you REALLY need to say...try these letters from Ballard or these zinc letters Anthropologie or these galvanized ones (only spelling "cool") from Pottery Barn. Good ol' PB also has many that are better suited for children's rooms.
~Images: 1) via Pinkwallpaper 2) Designer Morgan Harrison 3) Better Homes & Gardens 4) Home Magazine 5) Coastal Living 6) Pottery Barn