When animating you may find yourself needing to switch the current setting for tangent types quite often. Whenever you use the 'S' hotkey to set a keyframe, Maya will use the tangent types you have specified in the Animation Preferences. Opening the preferences every time you want to set a different type of key can get irritating.

Above you can see my marking menu for tangents. Simple enough, except that figuring out the MEL command to put into the marking menu quadrants is not all that easy since they removed the tangent pull down menu that used to be in 1.5 and earlier. (why'd they get rid of it eh?). So if you jump to the Scripts section you'll find the mel commands in there which I turned into global procs.

 

If you have never made a hotkey driven custom marking menu, go to Options/Customize UI/Marking Menus. Hit 'Create Marking Menu', then right click on the quadrant you want associate with a MEL command and chose 'Edit Menu Item'. Then in the Commands field, type the MEL command you want in there. For example, the MEL command for Spline tangents is:

keyTangent -g -itt spline -ott spline;

 

Then set the marking menu to be 'Accessible in Hotkey Editor', jump to the Hotkey editor, scroll to the bottom of the list, and assign hotkeys for both 'press' and 'release' to your marking menu.