Contacts as an expendable resource

I've seen a lot of roleplaying games handle the idea of having contacts -- people in high (or low) places who consider you a friend, or owe you a favor -- in various ways. One way occurred to me today (while people were watching the movie Taken, in which our hero uses several contacts from his past) which seems very simple, and very in line with a lot of the "authorial control in the hands of players" systems that are more common and more accepted, but which I haven't seen. I've no doubt that's just because I haven't happened to have seen the games that do it this way, though.

In a sense, it's a more specific and focused variation on the "plot point" idea. Contacts should be something you buy in advance in a particular quantity, but where you don't specify ahead of time what the contacts actually are. During play, you'll expend -- use up, and lose -- some of the points you have in contacts, every time you choose to call on a contact. You'll make up, on the spot, who the contact is, what your relationship with him is, and how he can possibly help; and the number of contacts points you'll spend depend on how useful he is and whether the favor you're calling in is likely a one-time thing or not. Of course, you'll also have to make it plausibly fit your background.

Contact points would also be awarded at the ends of adventures for anything you did that possibly means someone owes you a favor. If you saved anyone from peril or embarassment (and don't your characters often end up saving someone from something?) and they happen to be aware of it, you'll earn as many contact points as it would have cost to call on that same person or organization. Note that you don't need to actually spend those points later on that same guy (though if you did that would be fine). If you just saved a software company CEO from losing control of his company to a hostile takeover, next adventure, you can use those contact points to call on a software company CEO, but you could also use them to call on a guy you worked with once who can get fake IDs.

There's no reason you couldn't use something like this in just about any game, and if it has a point buy mechanism, you can let people buy a certain number of contact points with their character points; if not, just give out a starting number and then let people earn them from there. All it would take is some guidelines for how to tell how many contact points a particular contact is worth, and you're set to go. I will need to write up some such guidelines and start using this in my games forthwith. (Though it might be of relatively little use in the dimension-hopping game, come to think of it.)