To avoid driving back to external lists of users each time I create a session, I started utilizing "groups" to store these users. It took a while to set up as there is no mass import option (another feature to add!). Once assembled, adding users is as simple as a couple clicks on the desired user groups. When explaining it to my peers, we tried to find a "share" function for the groups but were unable to find anything.
It would be extremely beneficial to allow us to share the custom groups that we have already created with others. Trying to get IT to create individual email distribution lists for us to use from the "address book" option is likely more difficult than moving a river.