Fetch as Googlebot - Submit to Index at Google function in Google Webmaster Tools. But you should if you are interested in speeding up the process of adding or changing URLs to be indexed or re-indexed by Google. This also is a great tool in helping you diagnose and debug hidden advanced hacks that the public and you do not see, but Googlebot does.
1) Index or re-index URLs on Google Immediately
2) Diagnose and Debug for Hidden Hacks
Search engine optimization is a competitive sport. Any edge that a developer or company can get is valuable. Many clients have asked us how to speed up indexing or "speed up Google". We normally say this is a process. But now Google does offer the ability to immediate submit to index with some limitations.
Normally you have to wait for Googlebot to come when it would feels like it and crawl your page content. Now up to 50 times per week, you can submit a URL to fetch as Googlebot and it will immediately submit that page to the index. This is great for brand new content item or for a change to a previously indexed page that has had changes. Also, it has another powerful feature which allows you to not only update the URL that you submit, but also update any on the internal indexed pages that the URL is linked to. This is controlled heavily by Google so that developers don't go crazy and is only allowed 10 times per month.
Great for Bloggers
When we post a blog such as this one, we pick a strategic time to post and promote the article. By using the Fetch as Googlebot - Submit to Index feature, we are immediately indexing that blog post at the time we would like. We are not Mashable, or Huffington Post, so Google visits us less frequently than mega blogs.
To try this, simply login to Google Webmaster Tools account (assuming you have already created one), select the site to manage and click on "Diagnostics" on the left side menu. You will see "Fetch as Googlebot" towards the bottom. Click on that menu item and add the URL in the form box. Then click on Fetch. In a few seconds, the URL will be added to the list below with either a Fetch Status of "Success" or "Failure". You can click on the Fetch Status to see exactly what Googlebot sees. If you get the status "Success", then click on the "Submit to Index" link to the right of the Success Status. This will immediately submit to the index at Google.
We recently had a hosting client (not our development work) that had been "advanced hacked". If you entered the site URL in manually, there seemed to be no problems. But if you were directed to the site from a link on Google search, you were immediately re-directed to a phishing site. Fetch as Googlebot was able to show us the hack as Googlebot saw it. We tracked down the hack and eliminated the problem. In this case, was a security hole in a non-updated version of Wordpress. To see this, you follow the same steps as above. Once you submit the URL to Fetch as Googlebot, you click on the Fetch Status link and you will see what Googlebot sees.
Here is the video introducing this feature.