We are using Sharepoint Portal Server 2003 and have numerous calendars placed on different pages / areas. We would like to have a webpart which works exactly like the current calendar webpart, with all its functionality, buttons, etc, but with one important difference - it should be a sum of all the other calendars on the site. We should be able to choose, via the properties, which calendars from the site it is a merge of, so only the calendars of our choosing show up. Then it should show all the listings from all the calendars in the one calendar, differentiating them by color. When an event is created on that calendar, one of the fields should ask which calendar the event should be based in, so then it gets put into one of the calendars that the merged calendar is using.
You'll need to use your own .NET and whatnot, and deliver an executable package that does all the installation, granting of permissions, etc. The end users of this have no administrative priviledges, do not know html, etc.
If you have any questions please let me know. Also, please tell me about any projects you may have done in the past which are Sharepoint related, as we're always looking for new ideas. A bonus will be awarded if you can think of additional functionality that you would also build into this Merged Calendar.