I created this presentation for a client, about the 3.0 features in OpenOffice.org. I'm going to do a more detailed article but I thought I would post this since I've done it. Here's the solver.ods spreadsheet you can use to fiddle with.
I got pretty excited about some of them, especially the 3-up layout with lines already in there, and the far easier Impress handout printing.
And for those who like a good cross-reference, you don't need to create them first; you can just point to a heading in a list and select it, to make the cross-reference.
Also very exciting is the PDF editing, which does some very Adobe Acrobat type things. It's in an extension you can get here.
In the words of Douglas Adams, share and enjoy!