Ok, version 0.1.0 of Lanterne is now on its way up to extras-devel. From the pull-down menu, you can now select "Morse Code", which will bring up a window with a text entry field; type your desired text into this field, click "Transmit Code", and the LED will flash out the characters for you.

There is also a "Dot Duration" spinbox; you can use this to determine the length of a dot. (A dash is three dots, dashes and dots are separated by a dot-length pause, characters are separated by a 3-dot-length pause, and words are separated by a 7-dot-length pause.)

This is just standard Morse alphabet, taken off of the Wiki page for Morse code. I haven't tried to add any internationalization or shortcuts or whatever (and I probably don't know enough to do it right anyway). But, at least, it should support the basics.

Now, the _really_ interesting app addition imho would be to have the N900 read incoming morse code, not just transmit it. Dunno just how much effort that would take, though...