- Download the free InDesign script called CornerEffects.js. (You'll need to sign in with your Adobe ID.)
- Load the script into InDesign.
- Open InDesign document and draw a rectangle (or other shape) or select a photo.
- With the shape or photo selected, double-click the CornerEffects script. A dialog box pops up and you can choose which corners you'd like to round.
Note: Since this script manually creates the points for the rounded corner shape, the final corner effect not flexible/editable like InDesign's built-in rounded corner effect. Therefore, I would highly recommend you make a copy of your original photos onto a separate layer before applying the rounded corner script.
Update: InDesign CS5 now has the "round any corner independently" option built right in!