Today, in a post in the MSCRM 3.0 Developer newsgroup, Simon pointed out that their was no reference to capture the Save and New button event.

The SDK documentation for the OnSave event lists the following event.Mode values:

CRM_FORM_SAVE_MODE_SAVE = 1
CRM_FORM_SAVE_MODE_SAVEANDCLOSE = 2

I put the following code into the OnSave event of a form:

alert(event.Mode);

and found that Save and New generates a Mode of 59.

Write that down somewhere in case you need to capture that event.