A while ago, a user asked me why he wasn’t able to add a task to a default SharePoint tasklist and assign it to multiple persons. I wasn’t sure about this so I checked myself and indeed I wasn’t able to do this either. For some reason I didn’t really look too hard and didn’t found a solution, but luckily Bart pointed me in the right direction. The (quite easy) solution is to alter the ‘assigned to’ colum via the list properties. There you may set the ‘allow multiple selections’ property to true to enable users to select more than one person or group.
Maybe not that astonishing, but I couldn’t find this one at first so maybe this post turns up in your search results while looking for the same solution 😉
By the way, this solution doesn’t always apply. For instance, in the profile properties of a user there’s a column named ‘Assistant’. This column is also of the ‘Person’ columntype, but you cannot set an ‘allow multiple selections’ property here unfortunately. But hey, who needs multiple assistants if they’ve got SharePoint and Office? 😉