I created a new gallery on my Web site for flower photos, and have just today uploaded 80 or so images . These were taken with a variety of cameras, even a couple of point-and-shoot cameras. But perhaps my favorite technique at the moment involves hand-holding an Olympus dSLR with a 70-300 zoom lens and shooting at about 1/250th second to eliminate any subject motion from even the slightest amount of wind.
At 150mm with this zoom lens there is a 1:2 macro setting which basically fills the viewfinder with a 3" flower at a focusing distance of about 33". Since many of my flower images are taken in public gardens it is important to stay on the marked paths. This Olympus lens gives me the reach I so often need.
Here's a direct link: