also, to the point of the bit of work to write and manage code hitting the various external API's... most times the developers for these organizations have crea

also, to the point of the bit of work to write and manage code hitting the various external API's... most times the developers for these organizations have created well documented API's and code samples for simple implementation of their features on other sites... so it's not like you're reinventing the wheel (although facebook has caught some flak on here for the way they up and changed basically everything about their api and authentication and whatnot when they implemented the social graph, but I've worked with it a little and it doesn't seem that bad).