QuickSave plugin for ZBrush3 replaces the old PSnap button set. Unzip and install QuickSave.zsc in the ZStartup\ZPlugs folder. Next time you startup ZBrush3 you will find seven buttons in the ZPlugins menu under the Svengali subgroup.
Image and I+ buttons
First, the Image button lets you save the canvas image as a .psd or .bmp file.
After that, the I+ button will save new versions of canvas image incrementing the original filename. Tree002.psd, Tree003.psd and so on.
Model and M+ buttons
First, the Model button lets you save the current model (tool) in the directory of your choosing. Models are automatically saved at the lowest SubD level. If more than one SubTool is present, the top SubTool is selected and given the file's name, after which the original SubTool is reselected.
Any subsequent saves with the M+ button will increment the root filename, assigning that new filename to the top SubTool.
Docum and D+ buttons
Here, you save the current Document (.zbr) to the directory of your choosing. Note that if a model is active, it WILL NOT appear in the document file, but will be restored afterwards, same location and size, in edit mode.
The D+ button will incrementally save subsequent document files.
The Seventh button, QS-Help?, elaborates on this info about each button and how it works.
To use QuickSave, I drag all buttons (except for QS-Help?) to my User Interface (as shown).
*** A CAUTION! ***
I strongly recommend that you TEST THESE BUTTON-SAVE OPERATIONS WITH NON-CRITICAL FILES UNTIL YOU ARE CONFIDENT THEY WORK AS EXPECTED. And please, if you find any problems report them here.
Thanks to Marcus Civis and Aminuts for extensive testing and various feedback... appreciate it guys!