Sometimes; I picked up an old auxiliary rangefinder a while ago, and sometimes I bother to carry it along, sometimes not. It does help a lot with close-up and/or wide-open situations, but it takes some extra time to transfer the reading. They can be had cheap (bottom-feeding on eBay) and are worth having.
San Diego, CA, USA
The lady of the house has to be a pretty swell sort of person to put up with the annoyance of a photographer.
-The Little Technical Library, _Developing, Printing, And Enlarging_