It's not an official feature (yet), but Google Docs can perform OCR image-to-text conversions on high-resolution files you upload to it. They have to be pretty darned clear and crisp, but it's a nice freebie.
Those with webapps or services that upload to Google Docs can use this URL parameter to accept PNG, JPG,and GIF files for conversion, listed as an "experimental" feature at the moment.
Users, in the meantime, can try out a conversion using their own accounts at the Google Code Samples link. I tried uploading PNG screen grabs of Lifehacker and Wikipedia to Google Docs for conversion. Docs returned nothing with Lifehacker's text, and a somewhat muddled take on the Wikipedia entry for "life hack" with both PNG and JPG uploads (the full-quality JPG conversion, not pictured, fared just a bit better). Those were taken using nothing more than Ubuntu's screen capture tool and GIMP, however, so if you've got a better screen capture tool, or an actual camera shot of some relatively clear text, you'll probably do better.
Tell us how automatic Google Doc OCR might help you out in the comments.