For many things, the 3D viewport cursor designed into Blender is quite satisfactory. However, if one has a white background, as for example, if one is using a background image, the white-cursor-with-black-tips can sometimes become difficult to locate.
It would be quite useful, at least to this user, if the cursor could be made configurable, so that, if I am using a white background image, I could change the cursor to, say, a blue cross with orange tips, or ....
I have not checked but i believe you can change the color of the cursor in user preferences, let me look real quick. Well I don't see anything, sorry I wish I could have helped.