Seems to me this service has great potential for kids with learning disabilities. Might enable a sort of skimming for blind people as well.

techcrunch.com

Using semantic text extraction and personalization technologies, Topicmarks extracts text from the .pdf, .doc, .html and .txt documents that you upload, copy/paste, email in or enter the URL of. The service then gives you the option to view the “Overview,”"Facts,”"Summary” and”Keywords” of the document as well as “Properties” where you can see the original source. You can also interact with the “Overview” in a multitude of ways, including searching by key word and adding more or less text to the summary as needed.