I was using Google Trends the other day and thought, "If only I could have something like this for my analytics." For those of you who haven't seen a Google Trends report before, here is an example:

 

In the picture you can see the popularity of the keywords "csi" and "heroes" over time. Also marked on the timeline are news items related those search terms. 

How great would it be if you could add events to your analytics package whenever you make changes to the site you are tracking? You can then view your various analytics graphs (visits, page views, popular pages) with these events added to the timeline.

Some examples of events you might want to track:

• restructuring URLs
• using nofollow tags
• adding 301 redirects
• launching new site features
• creating linkbait

Imagine how you could use these in combination with segmentation in your analytics to see how each change effected traffic from difference sources. 

Whilst it is often easy enough to use analytics packages to track how paid campaigns are influencing your traffic, I haven't seen this sort of functionality available for SEO activities. This sort of overlay would be a very powerful tool for analyzing the success (or indeed failure) of changes you make to a site.