DD fan Michael Groufsky has created a "total conversion" and redesign of the Danger cards, giving them a snazzy look and resizing them for poker-sized cards, rather than the mini-sized cards which come with the game. They are available on BGG and Michael has given his permission for a copy to be hosted here.
Print those out at 100% scale, cut them out, sleeve them, and you're ready to go. Note that no card backs are included in that set.
Examples (scaled down):