Constrain to any 2 axes during transform? I want to be able to lock my translation/scale operations to two axes at a time, say xy, xz or yz. It currently takes two operations (one for each axis).

Example, say for a cylinder, I would like to reduce the radius. I currently have to scale on the x axis first, then on the y axis, or I have to manually input the scale values in the object properties panel.

This option is easily accessible in 3dsmax via the axis constraints command bar. Or I can click the intersecting area between the 3d manipulator of the axes in question and move in that plane.
While Blender doesn't have widgets to do this, its fairly straightforward.


Using the Manipulator: Hold Shift and click on the Grab/Scale handles,
X locks YZ,
Y locks XZ,
Z locks XY
Using Transform keys: Grab with G or Scale with S,
ShiftX locks YZ,
ShiftY locks XZ,
ShiftZ locks XY


As @sambler notes, you can do G Shift X,X move along the objects Local YX axis, works for any axis of course.