Want your gtalk to look like this?
Get the Mac OS skin for gtalk from here. I like the slightly gray look and the glossy green, red and orange buttons. Hope you like it too.
Update: No, don’t use this theme. It’s kinda too old and Google has added too many new features since then. You loose them all if you use this theme (the most important one being ‘send files’ option). Moreover, whenever you setup this version, Google soon automatically updates it to the original version. So absolutely no point till someone comes up with a modified theme.