Fast Crawling
Many people have noticed it occurring, and the change has been welcomed with open arms. Google updates its database on a monthly basis. When they update their database they will pick up any changes that you have made to your site. This gives people a window of opportunity to change things on their site to help them rank better, whether it be changing the design, cleaning up the HTML coding, changing the targeted keywords, or the keyword density.

This window of opportunity has grown larger, but only for some.

Google ranks pages by a factor called Page Rank (PR), which essentially calculates the authority of your website or web page. The calculation of PR is very complex, but for the purpose of this article the full understanding of the calculation is not necessary. Google has begun to crawl sites that it designates with a higher PR and as an authoritative website within a market, regularly, and sometimes daily. In some cases, it has been seen that Google has updated the cache of a web page in less than 24 hours.

There is a discussion regarding this topic here.
There is a very interesting paper regarding this topic here.

Indexing Flash Links
Google has answered the prayers of thousands of high-end designers that in the past were left in the dark when it came to the Google database and ranking. Google has begun to follow Flash links, but they still are not indexing Flash directly.

In the past Googlebot, Google's spider, would visit your site and find your Flash navigation or links, and it would not recognize them. The result would be that you index page would be the only page in Google's database, if that was even indexed. Now Google will follow these links, which will give webmaster's that utilize Flash the chance to have all of their web pages in the index.

The indexing of more sites that use Flash, and the following of Flash links, has two benefits. One benefit is what was stated before, which benefits that webmasters and optimization professionals. The other benefit is for Google. This will make their database larger; as well bring better search results to their users in the cases where the great information is tied up in Flash, or in deep level pages.

Indexing Dynamic URLs with Query Strings
As all good things come in threes, Google has begun to index something else that was very rare if not non-existent in the past: URLs with query strings and special characters in them. If you follow the link below, which is a basic search in Google, you will see a few listings of websites that use special characters, like the question mark (?), in the URL.

Basic Google Search

In the past, webmasters and optimization professionals were faced with the problem of making sure that Googlebot found and indexed these pages that use the query strings and special characters in the URL by using various methods. An example of one of these methods is to take all of the information and code from the dynamically generated page and place it into a static HTML page, which can then be submitted to Google. This can either be done manually or by using a form of scripting.

Now that Google will follow these dynamic links with special characters in them, webmasters and optimization professionals can be sure that their pages will be spidered by Google. As long as the information is market specific and the content is keyword rich, the chances that the dynamic pages will be picked up are higher.

Conclusion
The changes that are going on at Google are definitely for the better. While search engines like Alta Vista and Excite are falling out of the search engine race, the search engines that are left are those making improvements. Google is first in the search engines race because it appeals to both sides. Google appeals to the user by serving relevant results, and by finding the web sites and web pages that other search engines can't. They also appeal to the webmasters and optimization professionals by improving the way that they index websites and their relationship with the webmasters and optimization professionals.