Rated 5 out of 5 stars

This addon is great and fills a void I didn't even know existed. I live and die by gmail but I find spend a lot of time each morning just checking boxes to archive a large number of messages at a time. This allows a quick and easy way to select a set of messages at once. I would suggest that you try and add this feature natively into Firefox. It is unobtrusive and easy to use. The only thing I found is that it was a little lagy in GMail (but this is probably due to the JavaScript heaviness of it plus all the addons I have install for it) but it worked great (no lag) on all other sites. I do have one suggestion, by default it will toggle all check boxes in the selection, it would be nice that if you drag say holding the ctrl or alt key it would check all or uncheck all in the selection.