Slideshare is a great resource when you have some presentations or slide shows to share. Do you have a .pdf a .ppt or an .odp, upload it share it and all the people that were not at the conference can have some impression of what was presented.
Slideshare relies very much on community effort; I was told by pfctdayelise about Slideshare. I had a look and I like it for what it does. I have shared some presentations in the Wikimedia community.
There is one problem left. How do we share all our presentations? Where are all the other interesting presentations of relevance to the whole of the WMF community?
Currently there is talk about including social networking functionality to the WMF on the foundation-l. I would welcome it because currently many of us use such functionality and our community is fractured over the many different networks.