Google Cache Mapper is a Greasemonkey script that enhances Google's cached pages by adding a virtual scrollbar with all the matches of your keywords. Google highlights your search terms using different colors and this script shows the position of the matches. The virtual scrollbar is clickable and it shows snippets for each match of your search terms.
Google Chrome has a similar scrollbar that uses yellow markers to locate the matches for the "find in page" feature.
The user script requires Firefox and the Greasemonkey extension.
Browsing the web using Google Cache