Google web search has a special cache operator that shows the version of a web page as it exists inside the Google cache. This version may [or may not] be different from the current version of your webpage or blog depending on when Googlebot spider crawled it successfully.Now there's some very important information available in the header of the Google cache page - it tells you the exact date when Google last visited your website for indexing.
For instance, the query cache:labnol.blogspot.com says that "This is G o o g l e's cache of http://labnol.blogspot.com/ as retrieved on 31 Aug 2006 09:26:39 GMT." - This is the latest date when Googlebot indexed this blog.
While the Google cache operator is an old news, there have been some signification changes made to the Google cache information page as mentioned by the Webmaster blog.
Earlier, the date on the Google cache page reflected the date when googlebot crawled and downloaded your website onto their servers. If the googlebot visited your site again after say a few weeks later, it won't download anything if your site content have not changed.
However, in the recent changes, the Google cache date reflects the date when googlebot visited or accessed your site irrespective of the fact that it found new content on your site or not.
Quick Tip: Use the Google Date Range Operator to determine which all pages of your website were indexed by google during a particular time period.
Google Spider View Tool: Robin Good points to a wonderful tool that will help you see your page the same way GoogleBot and other spiders would read it. This tool extracts all text from the page, without design elements like CSS or HTML tags, javascript, tables or anything else.
Important Note: There's no space between the "cache:" and the web page url. See example of cache operator on Google Guide.
