We had some non-jewish friends visit from England recently. After one came out of our bathroom, she asked, "what is the funny cup with two handles all about? We've seen them everywhere here." It was then I realized that most people have no clue how OJ's live literally according to the Bible. G-d says, the Rabbis explain, We do. Simple as that. (well, not always simple, but at least it follows, logically) So, when G-d commanded us to Wash our hands before we eat a meal and after we go to the bathroom, we believe he meant it. The question becomes HOW? I've seen many people wash their hands in public restrooms (or not...ewwww!) and everyone has a different way of handling it, that's for certain. So, we have a set way of doing it that has been around for centuries, that way, everyone is equally clean! That's what the cup is for. Just in case you've never seen one, this is what they look like:
Some are fancy:
Some are not so fancy: They all have two handles, one for each hand! This washing process is also called Netilat Yadiaim (Hebrew for washing hands). When you wash after going to the bathroom, you wash with soap first (like normal folks should) Then you hold the filled cup with the handles facing you in your left hand and pour the water on your hands alternately 3 times (3 on each hand). Then you can dry your hands off and say the blessing after leaving the bathroom. When you are getting ready to eat a meal (with bread) you fill the cup, but pour 3 times on your right, then 3 times on your left. After this you say a blessing for washing hands (Blessed are you L-rd our G-d king of the universe who has given us the commandments and commanded us to wash hands) and then silently go back to wherever you're eating and say the blessing for bread and have your meal.
What to do if there's no wash cup? Just wash your hands and put them under the running water the correct way. Or find a drinking cup or other vessel and do it that way. It's better to wash in some way than not at all.
Now you know! Feel free to ask for clarifications!