For representation of any dynamic query results at run-time SharePoint's Content Query Web Part (CQWP or ECQWP) is frequently used. But it has some limitations, however: The usual SharePoint list features such as views, sorting, grouping, filtering, notifications when changes are done via e-mail and RSS feeds are not or only partially available. More complex queries can lead to low performance and / or high resource utilization. The CQWP is a MOSS feature only and not available for the free Windows SharePoint Services. The SharePoint Content Query List by Layer2 solves all of these problems: It provides the full list based functionality, e.g. views, grouping, calculated fields and the data is always available with high performance.
Workflows and email notifications can be used to start business actions, if query results are changed.
The solution will be available in Q1/2010, please register to receive information and download as soon as possible.