This weekend I was able to search for more digital levels that have an
alternate zero feature. Using the following search criteria in Google:
+digital +level +"alternate zero" I came up with the following products that
might be worth looking at. I have not used any of them.

PRO 360 Digital Protractor
http://www.davisontheweb.com/showpage.asp?L3ID=534
http://www.irvansmith.com/catalog2/parts/setup_smart_level.shtml
http://www.essexparts.com/CatalogPDF/Essex_98~Tools.pdf

Checkpoint Inclo-Matic 600 Series
http://www.mytoolstore.com/checkpnt/680.html

It looks like these solutions are more expensive than the MD SmartTool
though.

Don Parsons
LNCE N198TD (Reserved)