Have a VoIP phone installed at the worker's camp. Start with a minimum of QR 200 daily budget, and given QR 10 worth of phone calls to 20 workers each day.

This will cost you the salary and expenses of not more than two construction workers, but would give the guys a boost.

You have to take into account that these guys work their behinds off to send less than QR 1000 home every month - a free phone call may not count for much, but at least it will give them something to look forward to in the evening.

You can pick your own method of choosing the 20 lucky workers that day, or increase the budget.

Best of luck
Salman