  We present a study of large-scale bars in the local Universe, based on a
large sample of ~3692 galaxies, with -18.5 <= M_g < -22.0 mag and redshift 0.01
<= z < 0.03, drawn from the Sloan Digitized Sky Survey. Our sample includes
many galaxies that are disk-dominated and of late Hubble types. Both color cuts
and S\'ersic cuts yield a similar sample of ~2000 disk galaxies. We
characterize bars and disks by ellipse-fitting r-band images and applying
quantitative criteria. After excluding highly inclined ($>60^{\circ}$) systems,
we find the following results. (1) The optical r-band fraction (f_opt-r) of
barred galaxies, when averaged over the whole sample, is ~48%-52%. (2) When
galaxies are separated according to half light radius (r_e), or normalized
r_e/R_24, which is a measure of the bulge-to-disk (B/D) ratio, a remarkable
result is seen: f_opt-r rises sharply, from ~40% in galaxies that have small
r_e/R_24 and visually appear to host prominent bulges, to ~70% for galaxies
that have large r_e/R_24 and appear disk-dominated. (3) $f_{\rm opt-r}$ rises
for galaxies with bluer colors (by ~30%) and lower masses (by ~15%-20%). (4)
While hierarchical $\Lambda$CDM models of galaxy evolution models fail to
produce galaxies without classical bulges, our study finds that ~20% of disk
galaxies appear to be ``quasi-bulgeless''. (5) After applying the same cutoffs
in magnitude (M_V<-19.3 mag), bar size (a_bar >= 1.5 kpc), and bar ellipticity
(e_bar >=~0.4) that studies out to z~1 apply to ensure a complete sample,
adequate spatial resolution, and reliable bar identification, we obtain an
optical r-band bar fraction of 34%. This is comparable to the value reported at
z~0.2-1.0, implying that the optical bar fraction does not decline dramatically
by an order of magnitude in bright galaxies out to z~1. (abridged)
