I am tring to create a new site definition but I want to include a custom navigation bar in there and I am not sure how to do that. I'll have a look around and see if I can come up with any answers.

26 July
OK, so it is easy enough to just add another navbar to the onet.xml which creates OKish with the site but if you change the navbar then the changes only take effect if you make a real change to that page and so for it to take effect on every page you have to make a change to every page and obviously this is not practical.