There are several options you can use. You can add Alfresco as an app in Connections http://www-10.lotus.com/ldd/lcwiki.nsf/dx/Customizing_the_navigation_bar_ic301
Another option is to create an iWidget for Alfresco and access it via communities (so you can map communities to an Alfresco respository).
I believe Alfresco has a CMIS connector. If so, another option is to have Alfresco pull files from Connections via CMIS.
Hope this helps. If you need more, let me know.