The Manual

This is the best SL resource I've seen for some time... The Manual: a list of 81 in-world activities ranging from easy (#1) to hard (#24) and the sublime (#28) to the ridiculous (#50).  Kudos to the guys at Leeds (@kisa and @cubistscarboro) for pulling this stuff together.

Facets of virtual worlds

Sarah Robbins' Virtual Worlds Facet Study is now available as a Google spreadsheet .  There's a lot of material here, covering 70-odd virtual worlds, so it's well worth looking at.