Rotate

This tool rotates the selected UV components about the UV coordinate closest to the pointer. Click anywhere in the Texture view and drag horizontally.

Double-click on UV Points

You can double-click on UV points with the Move, Scale and Rotate tools and the following dialog window will open:

The point on which you clicked can then be repositioned numerically in UV space.

Active Tool manager options

The same options apply as for the move tool.