Basically hashing is a form of non-competitive cross-country running with the main objective of working up a decent thirst. Great emphasis is placed on the social aspects - particularly the communal boozing session at the aprés-hash. It's a fun activity and not be taken at all seriously.

For a very good description see that provided by the Birmingham H3 on their local BBC radio.

Want to know more? See:

How It All Started... A brief look at the origins of this world-wide organisation.	A Guide for New Feet If you would like to try hashing you might find this useful. Or not!	Hash Hints A few words of advice before you begin...
A Guide for Hares Some hints for the not quite so new hasher in the UK.	More about Hashing Other sources of information on hashing: magazines, on-line mailing lists, etc.	Wikipedia on Hashing