We present a novel technique with which to measure σ
8. It relies on measuring the dependence of the second-order bias of a density field on σ
8, using two separate techniques. Each technique employs area-averaged angular correlation functions (
N), one relying on the shape of
2, the other relying on the amplitude of
s3 (
s3 =
3/
22). We confirm the validity of this method by testing it on a mock catalog drawn from Millennium Simulation data and finding a value of σ
8 − σ
true8 = − 0.002 ± 0.062. We create a catalog of photometrically selected LRGs from SDSS DR5 and separate it into three distinct data sets by photometric redshift, with median redshifts of 0.47, 0.53, and 0.61. Measurements of
c2 and σ
8 are made for each data set, with the assumption of a flat geometry and WMAP3 best-fit priors on Ω
m,
h, and Γ. We find, with increasing redshift, that
c2 = 0.09 ± 0.04, 0.09 ± 0.05, and 0.09 ± 0.03, and σ
8 = 0.78 ± 0.08, 0.80 ± 0.09, and 0.80 ± 0.09. We combine these three consistent σ
8 measurements to produce σ
8 = 0.79 ± 0.05. Allowing the parameters Ω
m,
h, and Γ to vary within their WMAP3 1 σ error, we find that the best-fit value of σ
8 does not change by more than 8%, and we are thus confident that our measurement is accurate to within 10%. We anticipate that future surveys, such as Pan-STARRS, DES, and LSST, will be able to employ this method in order to measure σ
8 to great precision, and this will serve as an important check, complementarily, on the values determined via more established methods.