Earth Day Network, one of our newer users, is hailing the approach of their signature holiday with multiple online actions. The action here is pretty straightforward as pertains the technics -- there's also a pledge to use energy-efficient bulbs, which is a basic signup page -- but it's drawing traffic from several enormous mailing lists looking for topical links and turning its supporter signup chart vertical. Hyperlinks are only the cyberfroth on the ocean of free publicity generated by this observance, a salty reminder of the power of dates and occasions (previously noted in this space in reference to (also imminent) "Tax Freedom Day"). The behemoth that today is Earth Day was manufactured from scratch in 1970, and while the sort of institutional muscle that it throws around now might seem unimaginable to groups in other fields, there's nary the cause going that doesn't have an extant or potential commemoration with which to colonize one or more dates on the calendar. Update: EDN points out another nice twist on a standard action page, soliciting pledges to deliver a topical sermon from religious leaders.