It's not uncommon for me to hear about some new technology product or feature, from some company other than Microsoft, and realize that it sounds very similar to something I've covered before. More often than not, that something similar from the past ends up being a Microsoft Research project.

We've covered this phenomenon before in the case of Apple's Magic Mouse. It happened again today with the announcement of Google's new "Priority Inbox," a Gmail feature that uses a variety of inputs, including user correction, to automatically determine whether a particular message is deserving of higher attention.

The Microsoft Research project this reminded me of is called Priorities. It uses machine learning to analyze messages and determine their importance, ranking them and in some cases sending a text message when an email is deemed particularly important.

Forms of the Priorities project have been available for internal use by Microsoft employees since the late 1990s to help manage their inboxes, and the technology has been released previously as part of the Outlook Mobile Manager, available here from Microsoft Research.

Here's the 2005 story I wrote about the project and the veteran Microsoft researcher behind it, Eric Horvitz.

Email overload has been a key issue for Microsoft's Hotmail team, which announced a series of features this spring to categorize messages from different sources, helping people clean their inboxes more quickly. But it will be particularly interesting to see if the company revisits or considers a broader rollout for the sophisticated Microsoft Research Priorities algorithms now that Gmail has debuted its new Priority Inbox feature.

On the subject of that new Gmail feature, I've been trying it out today, and it seems to be working well so far -- accurately spotting most of my important messages, and placing them at the top of the inbox, while and allowing me to click a "plus" button to improve the system when it misses a message I consider important (or a "minus" button when it prioritizes a message I don't care about).

Google says the feature will be gradually rolled out to users over the coming days. If you're a Gmail user, let us know what you think if you have a chance to give it a try.

Update, 6 p.m.: Addressing a question being raised by readers: Yes, Microsoft has been issued a series of patents related to its Priorities project.

Among them: Methods for display, notification, and interaction with prioritized messages ... Integration of a computer-based message priority system with mobile electronic devices ... and Use of a bulk-email filter within a system for classifying messages for urgency or importance.