So, aphoristically, I am giving away 95% of my computing power to accomplish nothing.
OK, so let's turn it off. Fire up YaST and go to System > System Services (Runlevel). Sorry, no entries for either strigi or nepomukservices or anything like that.
OK, so then let's uninstall it. Fire up yast2 sw_single and find strigi. OK, done, change the checkbox to an X and proceed.
Not-so-fasto. It wants now to also uninstall all of KDE4 and plasma!!
OK, fuggedaboutit, locate strigi and rename the executables to trash_strigi, and then do the same for nepomukservices.
Look guys, I know you want to be creative, but please try to let something be optional until proven worthy and popular. The idea of uninstalling all of KDE 4 and plasma just to get rid of one useless search engine is ridiculous.