Many software can convert .vob file. Some are slow and other's in real time. Based on P4 System. Look at the info...
http://www.vitecmm.com/public/home/products/dvdmmod.html?sess=1038277630
http://www.authoringware.com/junior.htm
http://www.authoringware.com/wise.htm
http://www.mydvd.com/plus/default.asp
http://www.ulead.com/dmf/runme.htm
http://www.dazzle.com/products/dvdcomplete.html