There is lots on the forums - and you can do a search on 'Flash' to narrow it down to see the 'pain' some of us are going / have been through. I'm sure some nice chap even posted a link to a .flv a couple of weeks ago [seems like months].
Anyway - its a new (chilly) day here in the UK try an xml load with this
msreq = "http://api.msappspace.com/opensocial/v1/viewer.xml?opensocial_token=" + opensocial_token + "&opensocial_mode=" + opensocial_surface +"&detailtype=basic";
Though what you can the do with the viewers userid will be another question.....and not one I can answer....
Eddie