One of the greatest things about Linux is that you can tweak almost every aspect of it, including the GUI. For users of Gnome, the Gnome Extensions (extensions.gnome.org) add many customization options without having to get our hands dirty editing code.
One that I find exceptionally handy is the Trash extension by Axel von Bertoldi. In Gnome 3.2 the icon looked like it does to the right, which worked out quite well for the themes and icons I regularly use in Gnome. And changing the icon on your panel is relatively easy.