aweControlPicker is a minimalistic, clean and versatile GUI Picker for Maya that works with any rig. Sporting a slick interface, easy Picker organisation, no-hassle access to important functions and unique features such as the built-in MarkingMenu, this script will take your workflow to a whole new level of awesomeness!
Copy the script file (aweControlPicker.mel) to your scripts directory.
Under Windows, this is located under C:\User\Documents\maya\201x\scripts
You can determine your user directory from within Maya by executing the following MEL command:
internalVar -usd;
Copy the PNG images from the icons folder to your icons directory.
Again, under Windows, this is located under C:\User\Documents\maya\201x\prefs\icons
You can determine your icons directory by executing the following command:
internalVar -ubd;
After that is done restart Maya and execute the following command:
source "aweControlPicker.mel";
To start using the script, create a shelfbutton with the following command:
aweControlPicker;
Finally, I've supplied an image called aweControlPicker.png 
that you can use as an icon for your shelfbutton.
That's it!
To learn everything about this tool, check out the extensive online documentation