TabCandy - a new feature is available for testing in Firefox 4 beta
A new feature TabCandy is still in development, but is already available for testing . TabCandy is similar to the mix of Expose and Spaces from MacOsX. For example, with a large number of open tabs, you can look at them "from above". In addition, tabs can be organized in groups, and focusing on working with one group, and the rest will still be open, just will not be visible. For a better understanding, watch the video: