Have you ever heard about bulk workflow tasks? Hmm... neither had I! In one of our analyses I read there was no out of the box solution to edit workflow tasks at the same time. I did some research and found that in some cases you have the opportunity to mark for instance 5 workflow tasks of a certain type as "complete" for a given workflow association.
It is a pity that there only one predifined workflow (disposition workflow) in Office SharePoint 2007 that supports that option. However, there is a way to accomplish this behavior. First, you have to build a "custom" workflow template definition that define task types as bulk editable. Then, you also have to build an infoPath edit form with different views (one for individual task editing and also one for bulk editing).
For more info, take a look at:
Bulk editing workflow tasks in Office SharePoint Services 2007
How to: define a worklow task as bulk editable