Have you tested the new FamilySearch Pilot Website?
It makes available the actual images on microfilms from the Family History Library (FHL) in Salt Lake City UT, or through a local Family History Center.
Since this is a pilot website, there are a limited number of FHL microfilms that are available to view. But there are a number of Cook County related microfilms that are partially indexed with links to the actual microfilm images. You can save these free images to your computer's hard drive.
Here's how: click on the map of North America at the Family Search Pilot Website. Scroll down the list of items for the US until you come to Illinois. Select the category you want to search. These records are not yet completely indexed, but you will still find a fair number of them. In the search result, click on the blue underlined name. It will open a partial transcription.
It is important that you click on the thumbnail image of the document, or the "view original image" link, to see the original document. You can enlarge the image as much as you want. You can also search by first name alone, or last name alone, which can be useful in cases where errors in transcription or indexing might make records hard to find.