In this exercise student get a chance to look at differences between Greek and English(UK/US) in terms of humo(u)r.
1 Hand out the Doonesbury (or any other English language) cartoon strip, deal with any vocabulary and grammar issues then ask students to see if they "get" the joke. If not, what makes difficult for them to understand. (British humour can be particularly insular).
Alternatively, ask them what problems they would have if they wanted to translate this for publication in Greece.
2 Hand out the Arkas cartoon and ask them to translate it into English (best done in groups). This one is very good for practising writing in different registers.
3 Again ask them what problems they faced in making the cartoon understandable (and funny) in English
These are quite long strips which would only be suitable for advanced level students, but the same thing could be done with Mickey Mouse or Charlie Brown cartoons.
The idea originally comes from Using Newspapers in the Classroom by Paul Sanderson.