Also written as SOAL or S.O.A.L, this slang term is used as an acronym in place of the phrase: "Stuff On Arms & Legs" or "Stuff On Appendages/Limbs." The former term is more common, though the latter is more accurate as it encompasses the neck, fingers and toes as well as the arms and legs. (Note: Soal is often mistakenly spelled as "Soul", though this has become acceptable as the items are often referred to as a "piece of one's soul."
The "stuff" being referred to is jewelry typically hand-made by oneself or friends. These articles generally carry with them some sort of significance by marking a turning point in one's life, alluding to a certain outlook/way of living, or to aid in remembering a specific time.
Hemp bracelets, ripped bandana anklets, and twine rings all fall under the soal category. Sometimes purchased items may be considered "true soal" if they are especially significant and are of an "earthy" nature (such as hemp, twine, leather, wood, seashells, etc.). Other additions such as an iron ring on a necklace or plastic beads in an anklet may be acceptable if they were woven in by your own hand or that of a loved one. (Some consider hand-made duct-tape articles to be genuine soal, while even others accept jewelry made from old computer/car parts).
There are generally two types of soal-wearers; those with only one article kept for a special purpose, and those who collect soal in great amounts.
Soal can be fashionable or extremely gaudy. Usually, it's the latter.
"Did you check out her soal? It looks so stupid."
"Man, that is /not/ soal!"