We can easy to set css styles for html element, but when you want set some css(maybe background…) for input type=”file”, oh No, no good way to do this.

but some people fix this problem.

css way(+ a little javascript)
Styling File Upload Input Box in CSS
example here.

jQuery way
File Style
example here.

I think this jQuery plugin get a little position bug, need to fix. maybe I’ll do it.

Flash way
flash is good way to upload file(s) more than html, but you need install flash Player. SWFUpload is a small JavaScript/Flash library to get the best of both worlds. you can try it.