And if you're looking for a post in a specific forum, use these search terms on Google:

For example, to search the US Airways forum only for the word "upgrades":
site:flyertalk.com "Airline Programs US Airways Dividend Miles" upgrades

Or to search MilesBuzz for the word "credit card":
site:flyertalk.com "Miles&Points MilesBuzz" "credit card"

You need to type the words "Airline Programs," "Miles&Points" or "Travel&Dining" respectively, followed by the program name, to narrow your results down to a specific forum. Google includes the drop-down menu at the bottom of the screen that lists ALL forums as text on every FT page, so if you just type "US Airways Dividend Miles" or "MilesBuzz" you'll get pretty much every page on FT.