<div style="background:url(file_upload.png); height:18px; width:18px; overflow:hidden">
<input type="file" name="file" style="cursor:pointer; position:relative; top:-2px; left:-200px;
filter:alpha(opacity=0); -moz-opacity:0; opacity:0">
</div>
This code uses a 18px by 18px image to upload. If you want to use another image size will probably need to change the top and left position of the input file and make sure it works in all browsers.
Translated from Spanish with Google.
Category: HTML