Google's Gmail Priority Inbox feature is a nice little tool that lets users sculpt their inboxes in such a way as to make sure their most important messages are front and center while their least important exchanges are put on the back burner.

The software uses algorithms that sort incoming e-mail into sections deemed important and unread, starred, and everything else, based on messages users open and reply to.

This tool gets "smarter" with more use, and users can train it by clicking a plus or minus sign to sort content. Check out this screen I took after using the tool:

It's neat, but not exactly earth-shattering. Gist, Xobni, Liaise and several others are doing things to build a more intelligent inbox.

The key difference is they don't have the network to support their products; they depend on Microsoft Outlook, Gmail, Yahoo Mail or other clients to work.

And while Microsoft has added an Outlook Social Connector via LinkedIn to socialize its inbox along with myriad other filters, it doesn't have the same sort of filters Google has added to Gmail to prioritize messages.

I spoke to Google Enterprise Group Product Manager Rajen Sheth yesterday about this tool.

I argued that the casual consumer may not have much use for this tool, but the hardcore business user -- the individual who uses Gmail as a messaging client for work -- will have a field day with it.

As such, this is a major tool for Google Apps users who receive hundreds or thousands of e-mail messages per day.

Sheth told me that he originally thought Priority Inbox would be "most valuable in a business context." However, he had a change of view after using it:

But then I looked at my personal inbox and I realized how valuable this might be for my personal inbox. I'm looking at my personal inbox right now and it's a combination of important things sent to me from my family or friends, mixed with messages from various Websites that I've bought things from; Amazon, or Facebook notifications or LinkedIn notifications that I don't want to filter out ... but I don't see as the same importance as some of the personal messages that are sent in. In that regard, I think it's going to be valuable for consumer users too.

Fair enough. I respect this view. Having used it for the last 24 hours, I can't say I share the same experience. That's because I don't conduct a whole lot of personal correspondence via Gmail.

In fact, I exchange more content in Google Buzz than Gmail! But Buzz is not Gmail, even if it leverages its network.

I use Outlook 2007 with Xobni Plus for work, Gmail for my personal e-mail. I can say Gmail Priority Inbox works, but there are only so many Amazon book suggestions I need organized each week.

I do most of my personal messaging through Facebook, not Gmail. I use Gmail as my de facto e-mail account for e-commerce stuff, but when it comes to sharing content, I'm primarily a Facebook guy.

I suspect many of the 500 million Facebook users who have Gmail, Hotmail or Yahoo Mail do something similar. Sheth is a Google employee, so I'd be shocked if he used Facebook and not Gmail or Buzz as his social networking service of choice.

Still, the fact that I use Gmail primarily as an e-mail account for notifications and use Facebook as my content and communications repository probably illustrates a big reason why Google will have a hard time competing with Facebook in social. But that's another story.

It's probably best to view Gmail Priority Inbox from the perspective that Google is improving Gmail to challenge Microsoft Outlook 2010 and SharePoint 2010, as well as Office Web Apps, which is threatening Google's Apps cloud collaboration stronghold.

Earlier in August, the company let Chrome users drag e-mail attachments from Gmail to the desktop, improved the Gmail compose button and added Gmail Apps Search to let users search Google Docs and Google Sites.

Last week, Google added Call Phone for Gmail to let users call mobile phones for free. A great feature, I must say.

So, the Gmail functionality is definitely ramping up. With Google vying for the General Services Administration's e-mail and collaboration contract along with Microsoft and IBM, it will certainly help to add such functionality.

I'm still not sold on the value of this tool for the average consumer, but it will be a boon to the knowledge worker.

Check out how Gmail Priority Inbox works here: