I like to carry 5 spare rounds in a second gun, at the moment a S&W 37-2 Airweight, as its faster to draw it than to reload my SP101 with any method I have ever tried. I just got myself a 3" SP101 to go with my 2 1/4" DAO, so I expect now I'll be carrying a pair of SP101s instead of a SP and a J-frame.
I do carry spare ammo too though, a single speed loader in a belt pouch behind my belt gun, and a speed strip or two in my jeans watch pocket.
I don't have any problem carrying the DAO SP101 in my pocket, so I suppose I could move the J-frame to my ankle and carry three revolvers, but I doubt that will happen often if at all.