Just an FYI, I've gone ahead and submitted Lanterne 0.5.4, with a "sleep timer" ability; you can set a timeout value (from 1-120 minutes) on the Preferences window, and any torch activity after that (normal, pulsed, or SOS) will stop when the time runs out.

Unfortunately, the autobuilder is apparently out of commission right now, and with all the other interesting things going on in the Maemo community this weekend, I have no clue when anyone will get a chance to look at it...