I just wanted to give every Maya user out there a notice about a script I've made that you should check out:
Description: Nightshade UV Editor extends the default functionality of Maya's native UV Texture Editor with the following tools:
-Straighten UV shell: Straightens a shell along an edge loop or ring, and unfolds everything around it.
-Orient UV shells: Orients UV shells so that their bounding box is as small as possible. Almost always results in straight shells.
-Orient edge: Orient UV shell so that the selection runs horizontally or vertically. Great for custom orientation)
-Stack UV shells: Stack UV shells on top of each other.
-Match UV shells: Match UVs to their closest neighbors. Great to use in conjunction with "stack"
-Center UV shells: Places UV shells in the middle at 0.5u 0.5v
-Spread UV shells: Performs a UV shell layout that does not scale your shells or rotate them in a weird way.
-Rotate 90/180 degrees: Rotate shells CW or CCW 90/180 degrees.
-Tear off faces: Converts a face selection into a UV shell.
-Quick unfold: Buttons for quickly unfolding along U, V or in both directions with optimal unfold settings.
-Quick relax: Button for quickly relaxing a UV shell with optimal relax settings.
-Advanced UV manipulator: For quickly manipulating UV coords without having to type in new field values like a maniac all the time. In fact, you can do it entirely with just the mouse now - and even store manipulation values in variables for later use.
-Calculate UV utilization: Fast Python script by Guido Neumann that calculates how much space your UV shell scover (0->1 U and V).
-Measure pixel distance: Select two UVs and measure the distance in pixels between them. Excellent when you need to pack your shells tightly but want to avoid having to do a million snapshots.
-Powerful aligner: Aligns UV shells to the right, left, button, top or average U/V
-Push/Move UVs to average U or V: Maya has the tools for pushing UVs to the furthest right/left/bottom/top by default but it does not have the tool for pushing them to the average U or V. Now you have that option.
-Measure UV distance: Measure the U or V distance between two UVs.
-Retain component spacing checkbox: Now you no longer have to go into the Tool Settings window to toggle this.
-Integrated UV Set Editor: All the functionality of the default UV Set Editor is integrated. Also comes witha snapshot button.
-Texel density control: For quickly scaling UV shells so that they have the same texel resolution.
-Cycle edge colors: Change color on selected edges by switching back and forth between Maya's preset colors.
It's completely free and fully intergrated into Maya's native UV Editor.