Why Is "$" Dollar?

Well, the site has been up a couple of hours and a friend of mine already asked a pretty straight-forward question about YES, "why is the $ ("s") dollar?"
There is an interesting reason as to why we have, essentially, the letter s and a line through it ($) as apposed to a D with a circle- or any other geometric figure that may more accurately convey the word "dollar". The reason we have an s and not a D is because when America was being founded, as the phrase "not worth a continental" suggests, the continental dollars were becoming more and more worthless (the states kept printing money to help fund the revolution, but without much (if any) backing). At around the time the constitution was being implemented, the founders decided to make a new currency. Yet although there is some discrepancy with the details, it is widely held that the new currency was based on the Spanish dollar, that was already under circulation in the Spain-run colonies of the Americas. Therefore, it made perfect sense to the founders to adopt an $ onto the currency. By doing so, they at once distanced themselves from Britain and created a stronger medium of exchange.