The thin waning crescent Moon occults (covers) Venus during daylight on March 5, 2008, for central and western North America and Mexico. The bright little planet will disappear behind the Moon's bright edge (which may be invisible in the blue sky) and will reappear from behind the Moon's dark edge.
But "bright" is altogether the wrong word for any part of such a thin Moon (only 5% illuminated!) in the daytime sky. The Moon will be just 25° from the Sun, and lower than the Sun to boot. Venus, with its higher surface brightness, is surely what you'll notice in your telescope or finderscope first.
For the times of Venus's disappearance and reappeance as seen from your area, see the tables of predictions for hundreds of cities and towns prepared by the International Occultation Timing Association.
In the tables, the time of each event is given in Universal Time in hours, minutes, and seconds. To get Eastern Standard Time subtract 5 hours from this; for CST subtract 6 hours; for MST subtract 7 hours; for PST subtract 8 hours. The tables also give the altitudes of the Sun and Venus above your horizon at the time of the event (in degrees), and the azimuth of Venus: the compass direction around your horizon, counting eastward from true north. (Azimuth 270° is true west.) These directions will help a lot in finding Venus. In fact, if your sky is not crystal-clear blue, you may miss the Moon altogether even in a telescope!