You can select points, edges and polygons in the Texture view or in the 3D view. The selected elements will be displayed in both views.
The following applies to all selections tools: hold down Shift to add to an existing selection. Hold down
Selected points or polygons are colored.
UV islands (connected UV meshes) can be selected as follows:
Double-click with one of the tranformation tools (Move, Scale, etc.) or Live Selection (in Use Edge mode) on a UV polygon or UV point in the texture view (don’t click directly on a UV point but on any area of the UV Island; otherwise a dialog window will open for the numeric placement of the point on which you clicked).