Social Media Engagement (SoME 2011) - It focuses on how to measure user engagement (captivated and motivated to participate) and satisfaction with social media.
SemSearch 2011 - The fourth workshop on Semantic Search. The most interesting aspect of the workshop is the data challenge. What I find most compelling is the manually constructed "List" or "Type" queries that are more complex than the other entity queries. The manually constructed queries utilize the attributes and relationships, which make semantic data unique, e.g. [Japanese-born players who have played in MLB where the British monarch is also head of state].
Social Media Analytics - is being taught by Jure Leskovec from Stanford. The slide materials are available online. Last fall he also taught a related class, Social and Information Network Analysis. He is current teaching a class on Mining Massive Datasets.
Web-Based Open Domain Information Extraction is being presented by Marius Pasca from Google. He will be giving a related tutorial, Web Search Queries as a Corpus at the upcoming ACL conference in Portland.
Latent Variable Models on the Internet - Amr Amhed and Alex Smola are presenting work on using Graphical Models on web data. From the description, we will describe inference algorithms for collaborative filtering, recommendation, latent dirichlet allocation, and advanced clustering models.
Social Recommender Systems - Ido Guy and David Carmel from IBM Research are giving a tutorial on social recommender systems. See also the recent SRS2011 workshop which was also organized by Ido.