Utilities with IP´s numbers

Hi, im new here, little english, anyways, i want to ask.

What could i do with anothers IP ?

I only try to get their location but i only can from huge cities, i can´t gets name like districs, states, etc, smaller location.
Apart from that, any benefits excepts "hacking" the machine, i am talking about "triangle" the locations, just that.

I was testing with my own IP and everything die in mi Internet Supplier "Telefonica de Argentina" and some wrong location like Uruguay ( I´m from Argentina).

Well, thats all, thanks any way.