Wow, I missed this post. Forgive me for bumping it, but I think this one deserves more attention. K7JLJ, thank you for referencing that site! That is by far the best to learn CW. Many people struggle with learning code because they think of it as something they learn at low WPM speed. In fact, it is the opposite. The human brain has little ability to count dits and dahs at more than a few WPM, but the language part of the brain can recognize the "sounds" of each letter much better at 20-30wpm. People attempting to learn morse code should not try learning it slow. Anything over 5wpm is impossible to effectively "count" dits and dahs making that strategy a setup for failure.
As for banging out code on a cellar pipe as Gracieboo suggested, that is totally impractical with CW. How do you differentiate between a dit and a dah with a knock? That is what "knock code" is for and is entirely different (and very common in submarines and prison cells).
As for the transmitter circuitry, it can be FAR simpler than most people think. A single transistor can be used to make a transmitter capable of CW, and with a bypass capacitor on the emitter resistor, AM modulation cam be achieved with audio input. Add a single reverse-biased (audio-driven) diode and suddenly the tank circuit is changing frequency with the audio input due to the diode junction capacitance (FM)!
And morse code isn't limited to radio, a simple 5mw green laser pointer can get you help if stranded in the middle of nowhere. Just point it in front of (not at) an airplane or distant car (minding the beam divergence so as to not blind the pilot/driver) and you will surely have your GPS location reported, and possibly, the message understood).
The important part of any communication is doing so on a frequency (or medium) that people will receive. 500kHz used to be monitored for emergencies, but now I am not too sure. I know there are a couple 5MHz frequencies that are monitored in Alaska, but everywhere is different. It is important to understand what frequencies are monitored before learning how to communicate on them. For example.... A friend and I were using handheld 5w marine radios on ch16 in southern MN (nowhere near an ocean or large lake), but when the I-35 bridge collapsed, the coast guard helicopters in the cities 100 miles away heard us and reported us to the FCC. The FCC then used their satellites to triangulate us and they knew within seconds evactly where we were transmitting from - quoting FCC regulations between threats while convincing us to turn off our radios! Id rather face FCC fines over death, so, there you go!. FYI, that last "top secret" satellite launched with ULA likely contained another 100m wide antenna array..... Wanna save yourself? All you gotta do is know who to piss off!