The Woolong (symbol: ₩) is the standard unit of currency in the Cowboy Bebop universe. Woolongs are rarely traded in physical form such as in banknotes and coins; it seems that the 2071 economy is based on digital cash.
The Woolong appears to be roughly at parity with the mid-1990s Japanese Yen, or slightly inflated. The latter might not be the case if we consider the probable increased cost of consumer goods in a spacefaring society. For instance, a watermelon in "Mushroom Samba" was ₩1000. Whereas in "My Funny Valentine", we see debts such as ₩30M for a house, and ₩7000 for pizza. In "Stray Dog Strut" the pet shop worker said that Ein could probably sell for only ₩200 since the Welsh Corgi is a common species.
If we assume the Woolong is at parity with the 1998 Japanese Yen, then conversion may be performed rather easily. A good rule of thumb would be to assume ₩1 is worth about 1¢ US, ½p, or a little less than €0.01.
Woolong.com presents Ethereum as the real-world Woolong. It previously featured Bitcoin as playing this role, and made the switch to Ethereum in December 2016.
The Woolong has additionally resurfaced as the currency used in Space Dandy, which features many of the staff from Cowboy Bebop.