There's no fast way to change easily and rapidly the users in the RapidBoard from JIRA (https://COMPANY.atlassian.net/secure/RapidBoard.jspa?rapidView=XX&projectKey=XXX).
What is being done currently is that we have to click another user (select) to show his/her tasks and click again the previous user to exit from his/her tasks (deselect).
It gets more complicated when there are a lot of users and the option of the list of users appears in the upper menu, above the Board of tasks.
It's a routine that is done everyday in the meetings and It would be nice to have a shortcut key like -> or <- or other keys in the keyboard that allow to switch the users easily, to see their tasks.