Post anything. Tumblr makes it effortless to share
text, photos, quotes, links, music, and videos, from your browser, phone,
desktop, email, or wherever you happen to be
post anything tool...twitter is just for text, diigo is for websites, tumblr is for quick posts for all sorts. water aid uses it. This is one of those things that may have to be played with later on. I would focus first on getting my learners trained in co-creating video, get a twitter (to learn & share) keep sharing on diigo.