What about Postcards? They are cheap, they look good, they tell stories and they can show text, pictures and context (what is essential for communication!). Postcards are cheaper and cooler than square and boring letters. You don’t need to fit any formal criteria, you can even put oddest materials into the postbox. Here i have a little collection of possible postcards.

A: A simple postcard with a mindbending citation i added myself on the front. I will send this card, but i still don’t know to whom right now…
B: A very custimized postcard. This is my entrycard from the MediaSpace-Festival i visited last year. The customization (showing my name on the front) was done by the woman who filled out the media-space tickets. A lovely story on each side.
C: Another great (retro?) technique for getting postcards: this is an analogue photograph that i took at the expo2000 in germany. Send your visual memories.
D: No use for old flyers? Why don’t send ‘em by post?

Postcards are even great for anonymous communication (especially for digital paranoids), that can be a real advantage against email. Visit the weblog Postsecret to see anonymous postards in action.

More advantages: the recipient will read your stuff, the recipient will love the work you made especially for him/her
Disadvantages: slow, you don’t know if it will ever reach recipient, low cost but cost often combined with the heading for the next post station / post box

PS: if you want to send me a card:
Martin Wisniowski
Schützenstrasse 42
67659 Kaiserslautern
GERMANY