SlickUpload 5.2 was just released. This version adds support for skinning the actual html file selector using any html you specify. The skinning works in IE 6+, FF, Chrome, and Safari 2+. Any other browsers will gracefully use the original downlevel behavor. To see this in action, look at any of the SlickUpload samples.
Breaking change: The SlickUpload.SelectorHtmlTemplate property is renamed to DownlevelSelectorTemplate, and the FileSelector.HtmlTemplate property is renamed to DownlevelTemplate.
To implement this in your application, simply add a UplevelSelectorTemplate definition in your page and add html to define what the selector will look like. For example, to use a button with the text "Add Files", your uplevel selector template would look like the following:
<kw:SlickUpload ...>
...
<UplevelSelectorTemplate>
<input type="button" value="Add Files" />
</UplevelSelectorTemplate>
...
You're not limited to just a button type -- you can use any text or images in this template.
As always, the latest version is available on the SlickUpload download page.