Years ago when I first signed up for long distance they gave me one of those personal 800 numbers. I used it once and it cost me something like $14 but its there if I would ever need it. have a calling card still too. Last few times I've stopped at pay phones the keypad disconnects once the call has been made so you can't enter the calling card number or voicemail password, and thats with the few phones I could find that actually worked.
Something I used to have in my truck that was stolen was a butt set , or telephone test set. Its like a telephone that has alligator clips on the end so you can open the telco distribution box and clip on a pair and make a call. Its called a butt set because it hangs from the service person's belt at their behind. I see them go on ebay cheap every now and then. Could also pick up a POT (plain old telephone) and clip the cord and add clips on it and put a switch for the button on it.