ipcalc takes an IP address and netmask and calculates the resulting broadcast, network, Cisco wildcard mask, and host range. By giving a second netmask, you can design subnets and supernets. It is also intended to be a teaching tool and presents the subnetting results as easy-to-understand binary values.
MindMeister brings the concept of mind mapping to the web, using its facilities for real-time collaboration to allow truly global brainstorming sessions. Users can create, manage and share mind maps online and access them anytime, from anywhere.