here are some flowers I modelled and textured and rendered made in blender 2.59
These actually look really good in the full-size. You could maybe add some bump or normal mapping to the center. It looks like a flat image texture. The pedals also look paper thin… which might be okay.
Are you using SSS? It’s hard to tell from this angle, and the angle definitely doesn’t flatter them at all. The pedal texture is really good though and those little curls around the ends are a nice touch. SSS would really seal the deal.