I guess this question is in two parts:
1) How do I make my own package to collect all the widgets etc that I create into it i.e.
js/dojo/foo/*
2) How do get new widgets that I create registered so that when the page is parse after it has finished loading my widgets get picked up and instanciated i.e.
<div dojoType="foo.wizzBangWidget" >Something here</div>
There doesn't seem to be anything around on it :(

is your 'foo' namespace a peer of dojo?
foo should be a peer of dojo/dijit/dojox in your directory structure, otherwise you'll have to use registerModulePath to set that up
I found that if I just /*
I found that if I just
in the header then it just works, but I would like some automatic way for this to happen. How should I use registerModulePath to get this going?
If your code is in
If your code is in js/dojo/foo/* (so foo is a sibling to dijit, dojox), then you do not need to use dojo.registerModulePath(). However, for all widgets you reference via dojoType="" on an HTML element, you have to have an explicit dojo.require() for the module. The attempted auto-loading of widgets based on dojoType is not supported in Dojo 0.9+.
Yes, I got it working now.
Yes, I got it working now. There seems to be a bug with this Drupal template (I think thats where it is) as when I click on the link to 'reply' directly to your last comment I'm sent to:
http://www.dojotoolkit.org/comment/reply/6636/14937
which is a white screen where as this replay was made from:
http://www.dojotoolkit.org/comment/reply/6636
and seems to work, but is not directly on your comment but the main post :(
Strange...?