Packet radio.
This involves hooking ridiculously outdated 1200bps modems up to radio equipment, and sending messages fairly slowly (120 characters per second ought to be quick enough for anybody) to people quite a long way away. I've even used it to have a conversation with someone in Norway, by repeating the signal through the radio in the International Space Station.

Yes, it's slow. Yes, the software is fiddly to get going. Yes, you do need a radio licence to do it (legally). Yes, you could just use the Internet. But do you know what? It's fun, and it feels like sticking two fingers up at expensive, filtered and unreliable Internet Service Providers. Log this, twats...
(gordonjcp, Thu 4 Nov 2010, 13:14, 2 replies)

packet racket
I used to spend far too much time on packet about 15 years ago (Christ, is it really that long?), then my PK88 TNC died and I discovered the internet and IRC instead.

I bought a new-to-me TNC a couple of years ago, but there is almost no packet activity in my area now. I never did get to try out the blisteringly fast 9k6.
( speedyballbangpots, Thu 4 Nov 2010, 13:35, closed)

Have a crack at the ISS then
It has an APRS digipeater and a mailbox on it. I can get through it with around 25W into a vertical dipole on the roof - no fancy tracking or rotators - from the north of Scotland. Anywhere further south and it would be even easier.
(gordonjcp, Thu 4 Nov 2010, 13:45, closed)