The following table indicates the default location for directories for various data types in Mudbox. Many of these directories can be changed to suit your requirements.
User preferences
/Users/<username>/Library/Preferences/Mudbox/<version>/settings
<drive>:My Documents\Mudbox\<version>\settings
(Vista) <drive>:Users\<username>\Documents\Mudbox\<version>\settings
Stamps, Stencils, Presets, Logs, Temp
/Users/Library/Application Support/Autodesk/Mudbox <version>
<drive>:My Documents\Mudbox\<version>\data
(Vista) <drive>:Users\<username>\Documents\Mudbox\<version>\data
Curves, Meshes, Effects
<drive>:\Program Files\Autodesk\Mudbox<version>
Trays
(Vista) <drive>:Users\<username>\Documents\Mudbox\<version>\settings\Trays
Textures
Mudbox files (.mud)
/Users/<username>/Documents/Mudbox 2009
Extracted ambient occlusion maps
/Users/<username>
Extracted normal and displacement maps
<drive>:\Program Files\Autodesk\Mudbox<version>\textures