I was trying to Google a NWA PK cert last night, and when I entered the number, PK272, one of the top listings was for www.flightstats.com showing the flight in question. I thought this was pretty neat, and saved a lot of steps logging onto the airlines website and so forth.

So, just enter the airline code, let's say Continental, and the flight number. IE CO212, into Google, and voila, click on what is usually the first search result, and there you go! If this has been around before, I don't recall reading about it on FT, or I'm becoming blind.