Transbar is a nifty little app for those of you who want to see a little bit more of your desktop background. It weighs in at just 88KB, and after a quick setup process you’ll be able to adjust the transparency of your Windows 2000/XP/2003/Vista Taskbar. This is, however, a little redundant if your Vista installation already supports the Aero Glass which not only makes your Taskbar semi-transparent but it also blurs the background a bit.
There isn’t a whole lot to this program as seen in the screenshot to the right, but I found that it can add a little "spice" to your desktop by letting some of your desktop background shine through. So give Transbar a try and make your XP Taskbar transparent…at least a little bit. 
Transbar [via Shell Extension City]
Yup, this is why i check this site. Great find!
Wow amazing find, ditto with Daniel, on a side note does anyone know where I can get some good themes for XP without any 3rd party software?
Thanks Daniel!
I think this post should have all the info you need, including links on where to get the styles:
[cybernetnews.com]
yeah, i downloaded his and is working well….
try [xneat.com] it adds transparency to windows taskbar as well as making it opaque when your mouse comes over it
plus a lot of other functions.