We're happy to announce a new web part from Lightning Tools, the Lightning Conductor Web Part. This web part allows you to aggregate list and library data from sites within a site collection, but more importantly sites across site collections.
You can get more information, a download trial, and see a screencast of the web part in action here:
http://www.lightningtools.com/pages/lightning-conductor-web-part.aspx
Also this works for WSS 3.0 as well as MOSS 2007 so WSS users can get a similar experience to the CQWP which is only available in MOSS.
www.lightningtools.com