everything is actually in a database. don't ask me how long the data lasts...
it's all computerized now. anything that involves computers has a trail. so... if you call me, given the right permits\warrants, i can find out where you called (or rather, where the call originated), but not necessarily who you are...
it is simple to make a call whose location has been disguised, you can make it appear you are calling from a different location fairly easily if you know what you are doing.
i don't know much about cell phone records though, but logically that can be tracked too.