As the title states. Here is an example: http://howdoipaywithbitcoin.com/invoice/index.php?product_name=Test+Product&description=This+is+a+great+product%2C+please+buy+it.&address=19kztY8dsvD7pQZBA7Da9RAnzD2FyfdadJ&value=10.00

The BTC price will auto update. I hope some of you in the marketplace board find it useful. You can create new invoices on http://howdoipaywithbitcoin.com/