I'm a huge fan of back dimples on girls. They're the interesting little indentations in the lower back, just above the butt (see example). I used to think I was the only one who liked them, but now I know otherwise! If you have any (non-porn) pics to contribute to this list—which is, as far as I know, the best gallery online—contact me. Or leave a comment of appreciation.
Also, if you like what you see here, check out Adey's site at backdimples.co.uk.
The phrase 'dimples of Venus' refers to the pair of sagittally symmetrical indentations sometimes visible on the human lower back, just superior to the gluteal cleft. The dimples are directly superficial to the two sacroiliac joints, the sites where the sacrum attaches to the ilium of the pelvis.
This term, while ostensibly informal, is not strictly slang, but is a historically accepted name within the medical profession for the superficial topography of the sacroiliac joints. The Latin name is fossae lumbales laterales ('lateral lumbar indentations'--literally 'ditches' or 'trenches').
Dimples of Venus are rapidly gaining cultural momentum as a feature which heterosexual men find particularly attractive in females.
Source: Wikipedia