So this is a quick and dirty trick for getting the GUIDs for a set of records in Dynamics CRM v3.
1) Create a view of the records you want the GUIDs for
2) Export as a Dynamic list
3) Right click on A2 and select ‘Edit Query…’
4) A bunch of boxes will pop up. Close them as soon as they open
5) You will now see in your workbook an extra column has magically appeared on the end. These are your GUIDs
In v4 things have been made much simpler. Simply export as a dynamic worksheet and unhide the hidden column at the end which is your GUIDs.