WSSv2 and SPS 2003 allowed end users to create simple connections between List View web parts to enable master/detail type views or simple filters of list items. In WSS 3.0 there is a now support for a lookup column to be multi-selectable which provides a UI like this…
http://www.wssdemo.com/v3Images/multiselect.jpg
You can now use the values in the lookup to filter the list view if there are multiple selections.
Demo page Jhttp://www.wssdemo.com/Pages/technologyresources.aspx
Note: I did find a bug if the detail part is grouped by a content type, the page will error (may happen for any group by view).
Oh, and one of the best pieces of .Net opensource used to edit the image. Paint.Net http://fileforum.betanews.com/detail/PaintNET/1096481993/1
Technorati Tag: SharePoint