Terrafirma is mapping tool for Terraria. It gives block information in the statusbar as you hover, lets you zoom and pan around your map, and can save your map out as a png. New features include textures and lighting.
The Terraria Inventory Editor makes it easy to start a new character from scratch if you like to just build things without needing to gather the materials, or if you are just impatient and want all the cool stuff now.