Hello r (cc: golang-dev@googlegroups.com), I'd like you to review this change to https://code.google.com/p/go.talks
LGTM
*** Submitted as http://code.google.com/p/go/source/detail?r=764d8c2ea85e&repo=talks *** go.talks/present: rename piper to messageWriter R=r CC=golang-dev http://codereview.appspot.com/6709043