I've a supercool contribution from Marc Leoka who has not only managed to fix the bug in SPSFAQ090125 but has sent me the fix! I've amended that SPSFAQ to reflect his addition. Thanks Marc, this will be very useful for lots of people. There are also two pieces of code that I have used myself on a number of different project so I think it'd be good to share them. Here they all are:

SPSFAQ090125 - Advanced Search Web Part
SPSFAQ090134 - How to display a dynamic list of all the categories in the workspace?
SPSFAQ090135 - How to display the values of a multivalue property?