Has anyone able to assign multiple users to a sharepoint workflow task using the CreateTask activity?
What version? WSS V3 or MOSS?
Is the "Create Task" bound to the Task List? If so then only one person at a time. Unless you have an AD group with a bunch of people or you modify the list to include SharePoint groups in the assigned to field.
I blogged a while ago about how to develop custom activities with multiple users. It's been a while since I've done this, so I'm not 100% sure if it's applicable to your question, but it's worth a try:
Multi Value Columns Solution #2 - Custom Activities in SPD
There's a useful discussion in the comments as well.
Hope that helps, - Lee
Sharepoint task allow the use of groups. Assign the task to a group and trigger the work flow when a task has been assigned.
Creating a group is definitely the way to go if any user in that group can close the task. On a side note if you need seperate tasks for multiple users, you can use a replicator with a custom activity / CreateTask activity.