I just upgraded from Sharepoint Services 3.0 to SharePoint Portal server 2003. For my surprise the Portal Server doesn't have the Gantt Chart webpart, a very important tool in our organization.. How is this possible .. anyway is there some way to export the gantt chart from Sp Services to SP portal server ..
you can check this links to know what I'm tslking about..

SharePoint Portal server 2003 - No Gantt chart??
melbsurfer
I wouldn't call it an upgrade if you go from WSS 3.0 to SPS 2003. SPS 2003 uses WSS 2.0 (the previous version) as a platform. If you 'upgrade' WSS 3.0 to MOSS 2007, it will contain the Gantt Chart feature.
For a Gantt Chart in WSS2.0/SPS2003, I would like to refer to Teun's blog : http://www.teuntostring.net/blog/2006/02/new-version-of-gantt-part-group-by-and.html
- Mart