It happens many times on IRC, IM, mailing lists, usnet or email that someone get offended by something that was intended to be funny.
But you find a bit annoying filling all your messages with childish smileys.

This is the software for you

It takes what comes in from stdin and evacuate it from stdout after adding some ":)"
It accept a numeric humorlevel as a parameter.

Synopsis

irony [humorlevel]

Example

iron-y 6 < resignation-letter.txt | mail -s "Good luck" boss@yourcompany.com