"Using Twitter for Curated Academic Content"
(Yes, you could do this or you could just use Zite or even Flipboard - apps freely available via iTunes. Mal Booth)
A post about how Twitter differs from Facebook re networking. This post is from an entrepreneur's perspective, but there are parallels here for researchers and the most agile and adept researchers also use Twitter in much the same way.
Tumblr is a growing social media platform that is a bit of a mix between Twitter, a blog and something like Flickr (as it is normally associated with images or short videos). It is suited to multiple platforms and cloud-based. It is a platform that may suit some researchers. Another multi-platform blog along similar lines is Posterous.