I've been using the abandoned shack near the yangtze memorial for my early-game supply dump.. it has a reloading bench right next to a nice ammo crate and a bed and such..
I talked to one of the named guys at Camp McCarran and because I had really good rep with NCR he gave me a key to a ranger safe house that he said was used to store supplies and rest. Have not been there to check it out yet.
They're not very useful. Since this game has safe lockers everywhere you can just claim any of the legion abandoned shacks, though you might sometimes spawn into enemies if you do.
You get a lot of free rooms throughout the game to be honest. By the end I had a safehouse key, a place in Novac, a place in Freeside, and two places on the Strip. C'mon now.
Myself, I keep stuff in the Lucky 38 suite, but until recently it was all in one of the ammo boxes in front of REPCONN testing site, mostly because the idea of fitting several sets of armor into an ammo box amuses me.
In F3 I used an abandoned campsite and a house to live in, raiders would spawn there from time to time but it was good for storing items and for sleeping when leveling up. Hotels cost too much in Rivet City and other towns and Megatons Common House isn't available for the player to stay at.
Good thing theres a lot of places to stay in the Mojave to keep sleep deprivation at bay.
I'm using a random house in Goodsprings Is this bad? I have stuff in a locker and after a few game days nothing has happened. Should I pull the stuff out in case it respawns?