I've uploaded thousands of high quality and FREE ppt templates for all kinds of topics. Some are super cool and really will help with language instruction and presentation. Become A Supporter and get all of these templates.
Happy hunting and I'll be putting up more shortly.
Are these all the PowerPoint backgrounds? I tried clicking on the link above, but apparently that webpage is being blocked by my school's server... I guess I'll have to try and see if I can access them from home.
These zip files are the same as what is in the link you couldn't access - so download these attachments and you should be set. Some nice backgrounds or all sorts. Get the full mediafire resources (when home) by clicking on the Supporters tab above and selecting Mediafire.