A new addition to the SharePoint User’s Toolkit: a Tasks Lists Roll-up Web Part. When placed on a SharePoint 2007 page (wss or MOSS), this Web Part will aggregate tasks from the current site and all its sub-sites.
After downloading the Web Part, you can add it to your page via the page import option, or include it in your Web Part gallery. This is a regular Data View Web Part, and you can later modify the layout in SharePoint Designer. Without SPD, you could also tweak it directly through the SharePoint UI, or even via a text editor.
Lists roll-ups are available OOTB in SharePoint, thanks to the Data View Web Part – no need for a Content Query Web Part (MOSS only) or third party tools. However setting a DVWP to work in CrossList mode is not easy, even for experienced SharePointers. Hopefully this preconfigured Web Part will give a jumpstart to your cross-list experience.
I’ll publish more explanations in the days to come. I also plan to add more options in the future, as well as roll-ups for other lists – feedback and suggestions are welcome!
In case of emergency
If your customizations break your page, keep in mind the contents=1 trick (explained for example at the end of this article).