hot signup form css

We have a simple signup form (first, last, email, submit button) that we use, and we want to rock out some better styles for it.

We actually use it on a couple of sites, and we want a few variations so that it looks good on a variety of different sites. I'm thinking three to start.

Here is our form:

http://pastie.org/private/cwqifwozv29pufvd84pw

It's very simple, and you can see that the CSS is even simpler.

We just want three style variations for it.  Feel free to get creative.  We like rounded and friendly, but we also like fresh and clean design.

We want the forms to stand out when on the rest of the web page but not to be too obtrusive.  They should have the look of a tasteful badge almost, if that makes sense.
The current width in the HTML provided is what we're working with now, but we want to also experiment with making it wider.

It would also be cool to see something with a bit heavier lines.

- Working css and any necessary images to make each of the three styles work
- styles that work with varying widths of the input elements.  If we have to widen or narrow the form a bit it should not break the style.
- One of the styles should be in the fresh, simple, 37signals style
- One should be a bit heavier and more like a wireframe
- One should be very minimalistic
- we like simple and elegant
- A bit of rounded corner action would be great
- Maybe even a custom submit button
- don't forget the styling of the error message text so that it matches.

- Nothing that looks too traditional.