In response to the question, "What can the Google toolbar do for me?", I'm going to first answer in the terms of search engine optimization.

When you first setup the Toolbar it asks you if you want to enable features for PageRank. This is a metric that Google uses to signify importance and value. This is used for search engine result placements and other things that could take multiple hub pages to explain.

I would also recommend checking out Wikipedia's article here

When you have this feature enabled it will tell you the PageRank for the webpage that you're currently viewing. This can be a really quick and easy tool to use for search engine optimization purposes. You can use this to quickly guage the competitiveness of market leaders. This can also be used to figure out which sites are truly utilizing SEO practices and those that are just getting ranked due to no competition for the term that you're searching on.

One thing to keep note of is that this feature is usually about 2-3 months out of date. They do this because the PageRank metric is a proprietary measurement used by Google. It's algorithm is very closely guarded. If it got out as to how they calculate that other search engines could copy it and I'm sure a load of folks would use that knowledge to abuse it as well.

Another slick tool that can be found under the PageRank tools is the "Cached Pages" feature.

The point of this is to see what Google has indexed for the PageRank you see. When you select to load the cached version of the page you can see essentially what Google used to measure and calculate the given PageRank.

Once you've selected to load the cached page you'll notice very quickly the change. You'll see a large blue bar appear at the top of the page displaying various pieces of info. from Google. Most importantly though you'll see the option on the far right to view the "Text-only View".

This loads only the text that Google saw on this page. This is the most important item. Since the textual content is the key to what terms you get found for when searched and also how relevant your site is to those terms, this feature can be highly effective.

Learning the layout of very successful websites can be a good strategy for you to use in laying out the design of your own website.

I'm not going to spend a lot of time here. What this does is search for what Google thinks are related pages that share similar content.

Basically, if you go to google and search related:http://www.yoursite.com you'll get the same results.

In the end though I find little use. I figure if you can straight up search for something you'll probably get better results in most cases. Plus, as I've said before with the Google Toolbar being 2-3 months out of date, what's the point in looking for related web pages that might have changed since then?

I would recommend sticking to normal searching over using this feature.

The final thing that I'm going to discuss on the Toolbar for SEO purposes is the Backlinks feature. Again, this feature can be found under PageRank tool on the toolbar.

When you select to view the backlinks for the page that you're viewing it will return the number of known backlinks. Backlinks are links from another website to the one that you are viewing.

Now an important note here is that Google interprets and counts Backlinks much differently than other search engines. The value that Google places on certain types of backlinks can widely vary depending on many quality points that are measure by Google. To learn more about backlinks I highly suggest you view one of my other HubPages on link exchanges.

Since Backlinks are another large component of how PageRank is measured this another key information point to take in when researching other websites.

If you are using a computer that does not have the Google Toolbar installed and you would still like to view the backlinks you can enter this into Google to get the same results: link:http://www.yoursite.com

There are quite a few other options available for the Toolbar. I do apologize that I didn't go into more depth as to some of the many other tools and functions out there.

To be quite honest, these days with the way that you can save hot bookmarks in Firefox and the inbedded search box on most browsers the rest of the features aren't as useful as they were a couple years ago.

For that reason I mainly focused on it's uses in terms of search engine optmization.

If you have any further questions about the Google Toolbar uses in terms of SEO feel free to post them in comments or request another hub and I'll do my best to answer them.

If you have internet explorer go here to download from Google.

If you have Firefox go here to download from Google.