First, let's name the beast: Google's spider that visits your site, analyzes the content and then categories your material for the search engine is called "Googlebot" (Google + robot). This isn't anything hidden, it's just useful to be able to differentiate between Google the search engine and the Googlebot that, behind the scenes, actually visits your site so that you can be found in the search engine.

If you've been doing searches online -- and I can't imagine anyone who hasn't! -- then you're probably used to just skimming quickly through the search results, clicking on likely matches and basically zooming off of the Google page as fast as you can. Next time, though, slow down a bit. It turns out that there's a lot of interesting information you can glean from Google search results, information that's there, but not necessarily obvious. Indeed, it's often the case that search engines overall, not just Google, make extra information available, we just gloss past it in our zeal to find the answer to our specific search.

To understand how to ascertain Googlebot visit frequency, it's important to know that Google keeps its own copy of every page on your Web site that it indexes in its own local storage, called its "cache". Your computer caches information too, which is why the second time you load a Web page is always faster than the first time you visit it. On Google, it turns out that if we examine the cache information, it will tell us what we want to know. But let me show you, rather than just talk about it.

For example, let's do a quick Google search on iphone help and see what comes up... ah, what a coincidence! It's my own Web site. :-)

If you do the search, though, you'll see that not only do you get the title of the matching page and a twenty or so word description, but there's other information displayed, in smaller type and a more subtle color.

The last line shows: "www.askdavetaylor.com/about_iphone.html - 30k - Cached - Similar pages - Note this", and it's this the last line I want you to focus on. In order, the information displayed is the actual URL of the matching page followed by the approximate page size (in this case, 30k), a link to the cached copy of the page (which is critically important for our detective effort!), a way to search for similar pages in the Google engine and, finally, if you're logged in to your Google account, the "Note this" link is a simple way to add this link to your Google Notebook, if you use it.

Click on the "Cached" link and you'll be shown an archived copy of the Web page from Google's internal storage system, with a long, complicated header that's oh-so-important to our quest. The first line says: "This is G o o g l e's cache of the URL as retrieved on May 16, 2008 07:00:18 GMT."

So there's your answer. This particular page was last crawled by Google on 16 May, 2008. Since I'm writing this on 23 May, this means that Google's snapshot of this page is only a week old.

You can use the trick of clicking on the "Cached" link for any search result you find and then easily identify how old that copy is in the Google database. If it's weeks or months old, it means that nothing's changed and that the Googlebot isn't visiting you very often. This can only be changed by updating your content with frequency.