The font family Barack Obama’s campaign uses for “change” is Gotham, designed by Hoefler & Frere-Jones. It was originally commissioned by GQ Magazine. This type foundry, run by Jonathan Hoefler and Tobias Frere-Jones, has produced some of the industries best work. I highly recommend you check them out. They also have a pretty useful blog.

By the way, I have had a lot of inquiries on the “Hopeless George W. Bush” artwork inspired by Shepard Fairey’s popular Obama design. Thanks for the kind words. I am offering the sale of the “Hopeless” and “Exchange” artwork on prints, t-shirts, ties and mugs here.
Feel free to contact me if you would like the design on any other products. Enjoy!
The Gothamist also has a nice piece about the font with a few samples of inspired New York signage.
During an interview for the documentary Helvetica, Jonathan Hoefler and Tobias Frere-Jones spoke about the creation of Gotham:
(Gotham)…sounds surprisingly Obama-esque. “GQ had a dual agenda of wanting something that would look very fresh, yet very established, to have a credible voice to it,” says Hoefler. It also needed to look very masculine and “of-the-moment.” Mission accomplished.
The NY Times wrote a short about Gotham as the typeface for the Freedom Tower memorial at the World Trade Center site:
Gotham, the typeface chosen for the Freedom Tower cornerstone at the World Trade Center site, is distinguished by the uniformity in the width of its strokes and the absence of embellishments like serifs.