Google has finally [released a Mac client for the popular Google Desktop][1] search application. The search and launcher tool is designed to integrate with Apple's Spotlight, the built in search tool that ships with Mac OS X.

With Spotlight already built in to the Mac OS, Google Desktop for Mac is not quite the must have application that it is for Windows XP users. Still, Google Desktop for Mac is not just a port of the Windows version, it integrates nicely with the Mac user interface and offers some compelling options not found in Spotlight.

Currently Google Desktop for Mac is limited to search functionality with no toolbar or gadgets support as in the Windows version. However, Google says that such features will be added at a later date.

Installing Google Desktop is simple, just [download the Google Desktop][2] and double click the installer. As with Spotlight, expect the Google Desktop to eat up a fair bit of system resources while it performs its initial index.

In a particularly nice touch, the Google Desktop respects your Spotlight privacy settings and will not index the folders you've told Spotlight to ignore.

Once installed, you can begin using Google Desktop by invoking the default hotkey -- cmd + cmd (the cmd key twice). This will bring up a bezel-type window with a search box. Customization of the Google Desktop is handled through a pane in the System Preferences application. Using the pane you can change the keyboard shortcuts, control how many documents are listed in the results and even integrate searching with your GMail account.

By default the Google Desktop lists the last ten items in a drop down menu. To get a full search results listing, there's a link at the bottom of the drop-down list. Clicking the link will open a Google search results page in your default browser and list all the apps, documents and files that match your search criteria, paginated out like normal Google web search.

The GMail integration appears to be limited to one account and so far I can't get it to work. Google Desktop does a nice job of indexing and integrating with Apple's Mail.app but no GMail entries have thus far showed up in my search results.

As with most Google search tools you can use operators like <code>filetype:</code> and other selectors to narrow your search results. There are also some Google Desktop specific search operators, see the [Google Desktop site for more info][3].

Naturally the first thing most Mac users will want to know is how the Google Desktop compares to Spotlight. But before I get into that I should say that I'm not a heavy Spotlight user so I may be missing some Spotlight tricks in which case please educate me (and everyone else) in the comments below.

The first thing you'll notice about Google Desktop versus Spotlight is that Spotlight's results are much better organized. Google Desktop lacks the nice separation of document types and clean layout. On the other hand Google Desktop gives slightly more useful feedback including the first bits of text in files, similar to the extra line of data in a Google search. 

Of course if you hit return in a Spotlight search you can get the same sort of preview from the spotlight window, but with the Google Desktop Search there no extra step.

In terms of speed I found Google Desktop to be significantly faster on a Macbook for pulling up the initial search results. Desktop manages to do this without putting a heavy load on my machine is equally impressive. Once it finished indexing Google Desktop uses no CPU time in the background and grabs a mere 11 MB of RAM.

The most significant and immediately obvious advantage of Google Desktop is that it maintains a cache of deleted documents which means you can search and find things you've deleted whereas with Spotlight, when they're gone they're gone.

Note for the tinfoil hat brigade: Google says they aren't tracking any of this data, but fortunately if the cache feature bothers you, you can turn it off. Unfortunately there's no fine grained options for the cache -- for instance it might be nice to cache certain types of documents but skip others -- perhaps in version 2.

As with the PC version of Google Desktop, when you head to Google's online search page you'll notice a new option -- Desktop -- has been added to usual list of Web, Images, News and Maps. The Desktop option allows you to quickly move between local and web searches without ever leaving your browser.

Ultimately Google Desktop compliments Spotlight more than attempting to replace it. If you're a heavy user of Google services or find yourself on Google.com all the time anyway, you'll likely enjoy Google Desktop For Mac.

[1]: http://googlemac.blogspot.com/2007/04/google-desktop-for-mac_04.html "Google Desktop for Mac"
[2]: http://desktop.google.com/mac/ "Google Desktop"

[3]: http://desktop.google.com/features.html#advancedsearch "Desktop Advanced Search"