This one is my favourite:
http://www.pbase.com/bret/image/76284507/original
I like how you've captured the delicate veins in the petals and how
the bright yellow stands out with a black background.

I know Macro photography has very shallow DOF and what is particularly
difficult is a moving subject with limited shutter speed,  but you
nailed it with flying colors.
http://www.pbase.com/bret/image/76284513
Great work on all of them!
Helen

   Feels like I could pick the flower right out of the moniter. Very
nice. Your angle of the field of view neede to be shifted a bit to get
the entire flower in sharp focus. Just a bit.

  Always a difficult shot using a fixed macro lens. That is why some
many use a tilt-shift macro to get the plane of focus. Nice use of
lighting to bring out the detail of the pollen.

  Was going to say it was a Madagascar hissing roach but then I
noticed all the extra legs. Feels like I'm riding it's back deep into
the earth. Reminds me of my caving days.

Well done. Great depth of field. Can see the grains of pollen all
around the little bugger. Don't know if it was possible but if you had
gotten a lower angle of view  off to one side might have made a even
better shot of the bugger.

 Glad to see you posting such work. Shows that you do try and expand
what you know and share that with others. You through out images to
all to see and see what information you get back. No harrassing, no
bullying and no proclamations of "look at me. I'm better than anyone
in the world" nonsense we have all seen. There is always someone
better.

I know I don't have to say but, Keep at it. Stretch the boundries and
see what happens.

Draco

Getting even isn't good enough.
But being better does.