Farmer's Market - critique welcome

So I went out to play with my new Rebel XT and kit lens. My previous camera was a Canon IS S2, so it's a little weird not having the mega-zoom to play with. Anyways.. what can I do to improve these pictures? Or do I just need to shoot a billion more things before I'm comfortable with the camera?

#1

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I really like that last shot. Its very ominous looking. Great mood... err bad mood eh you know what I mean.

1-3 are underexposed
4-6 are nice.

Thanks for the comments, guys. I was using the powertoys resizing tools to change the sizes on the fly, but the quality just became too grainy for me. I just resized the pics in photoshop. And...now #6 looks too huge. Blah.

i like 6. if you look at the fence and scroll down quickly, it looks like the fence is moving at you.

I'm all about #6. Nicely done.

#5..try making it B&W, could be interesting. Or just desaturate it a little for more subdued colors.

The others...keep shooting a billion things. LOL Keep up the good work.