ArcToolbox

ArcToolbox
ArcToolbox is a set of tools used in ArcMap and ArcCatalog to do any data manipulation, conversion, spatial projection, and spatial analysis of the data. Models can be setup in ArcToolbox to process multiple tools on the data in a continuous flow. New tools be can purchased as extentions or even created using Visual Basic for Applications, ArcObjects, or Python API.

ArcCatalog - Tools -Customize

Data frames
The following pair of commands that are accessible in the View category in the Tools > Customize dialog box have been improved:see "active data frame"
These commands are not in the default ArcMap user interface. If your maps tend to contain a lot of data frames, it can be useful to add these commands into any toolbar or menu. They provide a quick way to cycle through the data frames in your map making each one active in turn. They work in both data view and layout view. The default keyboard shortcut to cycle forward through the data frames is Ctrl + Tab (which you can customize via Tools > Customize in the usual way). This keyboard shortcut is available when the map has keyboard focus even if you don''t add these commands into your user interface.

Note: Two redundant commands with the same name that were accessible in the Page Layout category in the Tools > Customize dialog box have been removed from the product. If you added those commands into your user interface, you should use the ones from the View category instead - http://webhelp.esri.com/arcgisdesktop/9.1/index.cfm?TopicName=What''s%20new%20in%20ArcMap%20for%20version%209.1

toolbox!!!