For example, recently flew in/out of New Delhi, and Bogota, and wanted to get a sense of how and where to get a taxi or limo, which companies were more reputable, etc. Flying in/out of Seoul, wanted to check airport bus pickup locations, also best place to get a SIM card for my phone, etc. Things that aren't unique to any particular airline (really have nothing to do with an airline) but frequently get discussed in threads anyway. So in those examples I searched the forums for the national airlines of each country respectively.

Of course for that sort of info I start with Trip*advisor, but to be perfectly honest I find the level of discussion on Flyertalk to be more helpful than that other site.....

(On edit) to JBord - I agree that the Destinations forums on Flyertalk can be useful but they aren't as frequently visited as the airline and hotel forums, it seems. Just my observation.