A simple one. Sorry if you all know this already - but I keep coming across people who've missed it - so please read on.
You can easily hide the ribbon in any of the Office 2007 programs simply by double clicking on the tabs.
Thus
becomes
with just a double-click on the Home tab (or any tab).
Oh, and I assume you know you can customise the Quick Access toolbar easily enough:
As usual this Tip is covered under my 'well duh' Disclaimer.