Thanks everyone. I think Imagineer sumed it up best (and very politely!) This was one of my first go's at a 'studio' type shot, and couldn't get the lighting quite right. Plus, the choice of a white background probably wasn't the best choice.
I'm off to the 'Reasons why my shot didn't turn out' thread for more excuses!
Nicely observed but not entirely pleasing shot due to the soft focus and washed-out colours. the composition is spot-on but you really need to work on the focus and depth of field to get the most out of a macro.
I like th composition of the triangle of the watermelon poking into the frame, the single seed, and the simple white background. The lighting could be more interesting and the focus just isn't sharp.
nice idea. it's probably your camera that takes away from the shot (too much flash and not enough focus). all the same, great effort. this is probably something that photoshop could rescue well enough to put it on a wall. also, maybe back off just a bit to have a little more border to the right.