Sign-up to those Task Forces - and Context and Privacy Task Force separated

Everyone,

   Just to make sure we have a good idea of whose interseted in the
task force, please sign up using the wiki. If possible,  incude if you
can volunteer to lead the task force and keep track of delvierables,
and any other comments like scope to the wiki page.

Since there seemed to be consensus on keeping the privacy and context
task forces separated, note that I have *kept* them separated on the
wiki. I've left context blank except for some of Venezia's comments.

So, now on wiki we have

1) http://www.w3.org/2005/Incubator/socialweb/wiki/Context_TF
2) http://www.w3.org/2005/Incubator/socialweb/wiki/Context_TF
3) http://www.w3.org/2005/Incubator/socialweb/wiki/Portability_Architecture_TF