Hold 'Shift" to select multiple mailing lists when choosing an audience for Newsletters etc.
When mailing to multiple lists I can only select one list at a time currently, it would be great to be able to hold Shift and select multiple mailing lists so I don't have to keep going back to the drop down menu to select another list. Very often we're sending to 15 or more lists. This would also apply when selecting filtering on contacts. i.e You have to select each criteria separately rather than being able to select multiple mailing lists to filer contacts from.