DEFEATJOHNJOHN.COM is offering a $10,000 reward to anyone that can produce an IMB Selectric Composer (or any typewriter) from the early 1970's era that can reproduce the documents that CBS News claims are from President Bush's Texas Air National Guard days. Read the article at their website.
If you're still not convinced the CBS documents are frauds, look at this .gif image of a brand-new MS Word version of the memo, overlaid on the CBS version.
The similarity is uncanny. Far too close to be anything but a complete MS Word fraud.