T.K.
I would agree to leave it blank, but since you worked for temp agencies, why not list them. You, no doubt, gained some experience while going out to differant places. If you worked for 3 differant agencies doing customer service and clerical work , You could list for instance...
"Oct 2009-Oct 2010 Registered with X, Y, Z Temporary Service Agencies
Assignments included clerical and customer service duties.'
If you had assignments to good places you could even list them.
"Assignments included, clerical work for Coca Cola of Irving, Payroll services for Boeing International."
That way there is no gap and you get credit for working for all those big time firms! That would be especially helpful if you are applying for a full time job with a place you already temped at.