I should have mentioned this ages ago! John Boardley, founder of ilovetypography.com, developer Justin Stahl, and Kari Pätilä, co-creator of welovetypography.com have built a great typography iPhone app. Not only is the game addictingly fun, with three difficulty levels and over 600 typeface examples, but it's also absolutely beautiful to look at! Check it out here if you're even remotely interested in typography. Be sure to post your score on Twitter!