I'm currently in Seattle at our annual conference where all of the Academic Evangelists from around the world get together talk about what we've been doing and start to plan our activity for next academic year. As part of this we had a presentation on XNA where a great tutorial on creating a 3D XNA game was mentioned.
The tutorial was created by Dan Waters and includes both the source code for the finished game as well as a series of videos showing exactly how the game was created using the free Softimage XSI 3D modelling tool and XNA Game Studio.
This is a great resource for those looking at getting started with XNA or thinking of building a 3D game and best of all it involves both Guitars and Pirates... what more could you want!
Check out the tutorial here.