Creating convex hull in ArcGIS Desktop?

At version 10, there is now a Minimum Bounding Geometry (Data Management) geoprocessing tool which:

Creates a feature class containing polygons which represent a specified minimum bounding geometry enclosing each input feature or each group of input features.

However:

The Geometry Type (geometry_type) options CONVEX_HULL, CIRCLE, and ENVELOPE are only available with an ArcInfo license.

I've used Hawth's Tools "Create Minimum Convex Polygons" under the Animal Movements menu. You can use a feature selection within ArcMap.

There is such a tool.

Open ArcToolbox > Cartography > Masking > Feature Outline Masks