Constellational Astrology

The form of Constellational Astrology which I find insightful uses the sidereal zodiac, but does not simply divide the zodiac into 12 equal (30 degree) signs.
Rather, I attempt to identify the cusps of the signs according to the actual sizes of the constellations as they appear in the sky.
Furthermore, I limit myself generally to consideration of the Ascendant, Moon, and Sun signs in natal charts (in that order of importance).
I recommend A Psychological Zodiac (The Roots of Self and Society) by Angela Arnold for a great description of the zodiacal signs.
Here is a modified version of Astrolog5.40 to display positions constellationally (when '-sc' switch is used): astrolog.tar.gz
The included astrolog.dat file chooses the '-sc' option by default, along with a few other options I prefer.
Naturally there is some ambiguity about where the true constellational sign cusps are.
I have chosen to start the zodiac (Aries) with a -2 degree offset from the default that Astrolog uses for the sidereal zodiac.
Then I set the following sign cusps (in decimal degrees) using a sign_cusps array in data.c:
Aries0.0
Taurus24.6
Gemini61.4
Cancer89.1
Leo109.2
Virgo144.9
Libra189.0
Scorpio212.1
Sagittarius237.4
Capricorn270.8
Aquarius298.9
Pisces322.7