Slang use varies by country and even by areas within a country. Who uses what slang? Before, you'd have to read linguistic journals. Not any longer.
The Online Slang Dictionary now features SlangMaps: interactive maps that show you where slang terms are used.
Let me know what you think.
-- Walter (email@example.com)
P.S. The maps were created with submissions I've already received. Soon you'll be able to put yourself on the map. Stay tuned.