If you are in Bangkok, or planning on coming here, and you are concerned about which areas of Bangkok are currently flooded, this handy Bangkok Post map can help.
It will show you most of the north of the city is already underwater (Rangsit, Don Mueang, Chang Wattana, Pahonyothin-Ratchadapisek (north), Chatuchak and Din Daeng, to name just a few.
The flood waters are quickly traveling south into inner Bangkok though, so what is flood-free today may be underwater 2-3 days from now.
Keep checking back for updates.