Aileron is a free sans-serif, modern display font, coming in UltraLight, Thin, Light, Regular, SemiBold, Bold, Heavy, Black, & Italic.
Chris over at SpoonGraphics has made this Vintage Light Bulb Sign PSD file available free for personal and commercial use. The only thing missing is an exclamation point, but I was able to easily make one out of the letter I in the PSD.
Ever want to write something in your own handwriting, but not actually have to hand write it? Me too. I type much faster than I write. This site can create a font in OpenType or TrueType format of your handwriting for free. All you have to do is download a form, provide your handwriting sample, and upload it.