Water source for my bees

Bees need a regular source of water, just like all other living things.  There are many ways of providing water for them and there are many studies regarding what they like to drink. 
Ever since I have had my bees, I have tried to provide a source of water.
Initially I placed a  small basin in front of their hive, which they never used.  Then I was told that they like their drinking fountain to be out of sight of the hive and in sun.  So I made a basin that was placed behind the new rose garden, hidden by plants from the hive and about 20 feet away.  Initially it had rocks in it, then sand, then peat moss, then a combination of sand, rocks, peat moss and cotton rope.  I had to cover the basin with chicken wire to keep out the raccoons.  Then I tried filling the basin with salty water.  And still, the bees were getting their water elsewhere.
A couple of weeks ago, I draped a towel in an old plastic wastebasket filled with water instead of the basin.  The towel kept moist by osmosis, giving them a safe and easy way to collect the water, but no bees.
Then... a couple of days ago I had watered some areas of the lawn (part of a large project to improve the croquet court)  and bees were there collecting water.  Brainstorm!  I moved the water source onto the lawn and added a blue rag to the red one that was already there.  I figured that even though the bees find the water mainly by smell I would make it more attractive by using a blue cloth as well since they see blue and not red.  Then I moved the wastebasket to the side of the lawn, out of the way. 
And IT WORKED!

My high-tech watering station

Two customers

I plan on giving them a few days to become habituated, then move it a couple of feet a day until I get it back behind the new rose garden.