Charging LED Clock modifies the charging LED pattern to indicate time : The charging and battery full LED batterns blink to indicate the current hour and minute with 5 minute precision.

concept:
time display with LED. When the phone is on charge.

Why do you want?
when I go to sleep.I usually put my phone (N900) away from me.
because I can turn the alarm off in my sleep.
is convenient when you can see the time at a distance.

implementation
use Morse code (only idea morse code)
12 hour 57 minute
looks like this: -** -----****(*)** //- long signal LED * short signal LED (*)signal brighter //

does not look very comfortable.
offer a minute rounded up a dozen
that is
12 hour 57 minute = 1 hour (code: *)
4 hour 16 minute = 4 hour 20 minute (code: **** **)
9 hour 33 minute = 9 hour 30 minute (code: ****(*)**** ***)
12 hour 22 minute = 12 hour 20 minute (code: -* **)
3 hour 42 minute = 3 hour 40 minute (code: *** ****)

More info at talk.maemo.org