jO8 No, I don't. I see no reason why anybody should, apart from wishful thinking. After all, praying implies an expectation that someone or something will, on your behalf, break the laws of physics - and if that could be done there would probably no longer be a universe!
The only properly conducted test, involving prayer groups and patients recovering from heart problems resulted in those who were prayed for and knew it doing least well, and those who were prayed for without knowing it doing better but those who weren't prayed for at all doing best! Of course that was only one trial, and nobody took it seriously - but it was funny!
I think that when people pray over a problem, they are forced to put the problem into words, and thus come to analyse their difficulty - which can help them to solve it for themselves. Otherwise - it's mostly mumbling...