Yes, indeed, the Sacagewea Golden Dollar (coming from a coin collector like myself) has had production terminated for general circulation coinage (which means they don't make them anymore to be given to banks, etc, and ultimately, businesses (and you) nation-wide)... However, they still make them for inclusion in special collectior proof and uncirculated sets sold directly off the USMint site at
http://www.usmint.gov/. The Golden Dollar, as it is affectionately known, is given as change at many vending machines. During the program (2000-2001), the Mint encouraged people NOT to hoard them for possible collectible value, but rather spend them, circulate them, and make them Useful. However, as their production has been terminated for circulatory use, this urge may be taken null and void. If I was you, I would not spend it. As it was produced as legal tender, and for general use, but now are not made anymore for circulation, just keep it as a souvenir of sorts. However, if you encounted any vending machines that take 5 dollar bills, there is a very good chance (well, 100% chance) that if you give it 5 dollars, it'll spit out 4 Sacageweas as change. So, it is not an uncommon event, to be the recipient of a Golden Dollar coin. However, it is not a common event either. Use it as you may, it is legal tender and was the subject of a huge ad campaign that told Americans to Spend it. It was not meant to be a special collectors coin. However, nowadays, in a creul twist of irony, it might be just That.