Font Matcherator is a very useful tool designed by the guys at Font Spring, that can help you find the fonts used in images.
All you have to do is upload the image, and the tool does the rest. It recognizes the characters in the image and provides with a number of typefaces that match the style of the font.
The Matcherator also has a tag refinement feature to really let you drill down the results for those hard to match fonts. It can even match OpenType featuresVisit Font Matcherator