As I read this psalm (see Bible.com for text), I'm thinking of a discussion a while back on The Bible Answer Man broadcast, especially concerning the teaching by Joel Osteen that has become so widespread. I think this psalm was briefly alluded to as one used by Osteen, and if so, I think he's using it wrongly. Here, the righteous prosper because their delight and meditation center on God's law--his word, his teachings. I don't recall scripture ever promising wealth--it warns, in fact, against the ways in which wealth can become a stumbling block. And wealth is not, I think, the measure of the prosperity referred to here. While it can mean financial success, the Latin base of the English word "prosperity" translates "to render fortunate." The alternative meaning is "to thrive."
This day, may I focus on thriving by and in my relationship with Jesus. May he protect and guide me away from the way of the wicked, which will perish. I give my financial successes over to him, that I may prosper more in knowing and doing the will of God.