Most of my friends are SPs.
I've met them at music events (especially volunteering to help out throwing concerts), art events, at the gym or just taking classes together at college. I used to work with a bunch of SPs, and I noticed that a lot of them had in common a military background.
yes! you're gonna find SPs a lot within the music scenes. not so much in the emotional type scenes (emo,soft rock or whatever), but more so in the crass in your face types like punk, thrash, hardcore, gangsta rap even lol, at least in my oppinion. also in any other scene that sounds like it's got colorful, sultry, thick sounds like big band'ish, old 20s-40s or old school folk/country. i'm not just talking about finding ISFPs but i'm usually around a lot of xSTPs as well.
*update* well, seeing that you're a stay at home mom i should give you other options for finding SPs...just understand that SPs are very "hands on" individuals. You could find them anywhere, I'm sure, but a sure way might be to look at all "hands on" type activities. I feel a lot of musicians could be SPs, in particular drummers for example, because the instrument in itself offers a physical type challenge. Just look for people that like to and would rather be "doing something" than "thinking of doing something." A lot of handymen types are also xSTPs from my experience. They like fixing things and just working on things gives them a sense of accomplishment.
SFPs will def be a bit more emotional so may be better found in the arts and entertainment types of activities. STPs perhaps in the more adventurous less emotive type things, auto mechanics, carpenters, contractors, bikers, extreme sports...eh, just my 2 cents.