Google has added yet another feature to Gmail to protect against inadvertent mistakes. While it lacks the entertaining premise of the Mail Goggles, the new feature, named "Got the wrong Bob?", will likely prove popular with anyone who frequently writes to groups of people.
Once activated, "Got the wrong Bob?" alerts you if it thinks you've included an unusual recipient in the group to which you're writing a message. By keeping tabs on the groups you most often write to, Gmail becomes your eagle-eyed friend, alerting you when you've likely mixed up two similarly named contacts.
For example, if you were hosting a dinner with a regular gang of friends and wanted to invite your buddy Mike, but inadvertently included your obnoxious co-worker Mike instead, Gmail would double check with you to make sure you had the right Mike. A small alert under the address field pops up with the text, "Did you mean: X instead of Y"? Clicking X's name automatically plugs X's email address in the "To:" field, and removes the incorrect contact's address from it.
Don't become too dependent on these alerts; the feature works only when writing to three or more people, and thus you'll still have to pay attention when corresponding with one or two colleagues.
"Got the wrong Bob?" is a nice complement to an older Gmail feature that suggests additional recipients to a group email message when you may have left someone out. That feature, formerly referred to as "Suggest more recipients," has been renamed "Don't forget Bob." (Though I personally would have preferred "What About Bob?".)
To activate either feature, log into your Gmail account, click the beaker icon in the upper right hand corner, scroll down, and click the Enable radio button for "Got the wrong Bob?" or "Don't forget Bob." (If the beaker doesn't appear, click the Settings link and then click the Labs link.) Then click the Save Changes button at the bottom.