Jumping clogged calendars faster than a speeding T3 connection, this handy application from Mozilla will prove to be quite helpful. Lightning 0.7 is an extension for Mozilla Thunderbird that adds an integrated calendar to the email client. With Lightning, users can view both their inbox and their calendar at the same time and they can also perform detailed calendar searches. This version is compatible with computers running Windows 2000 or XP along with Mozilla Thunderbird 1.5.