For a little more than a year now I've been a part of the PASS BI SIG and have tried to contribute whenever possible. The SIG is split into several focus groups that meet on all BI topics. I help in leading the SSIS group. Today I actually had an opportunity to present to the Analysis Services focus group on the topics of Analysis Services Partitions and Aggregations which you can watch free here http://www.bidn.com/blogs/DevinKnight/ssis/306/anaylsis-services-partitions-and-aggregations-pass-session.
If you think you would like to present on any BI topic contact me and we'll get you lined up as a speaker (firstname.lastname@example.org). It's a great opportunity to share your expertise with the community.