There was a commercial during CNN's crossfire program today 9-22-03,
the background music was Jimi Hendricks version of the national
anthem.The web site being advertised was cumbackamerica.org, or
comebackamerica.org.I find no results for any of these versions, can
you assist?

The Adbusters Media Foundation (whose website is called
unbrandamerica.org) has produced an advertisement which features Jimi
Hendrix's version of the national anthem. Here is the text of the ad:

Because my country has sold its soul to corporate power
Because consumerism has become our national religion
Because we've forgotten the true meaning of freedom
And because patriotism now means agreeing with the president
I pledge to do my duty... and take my country back. 

According to the unbrandamerica.org website, the ad was scheduled to
air today on CNN at 4:30 PM (EST), which would have been during the
broadcast of "Crossfire":

"It's a go: Adbusters' Unbrand America TV Spot is poised to hit the
airwaves. We've wrangled a 30-second chunk of national airtime. More
than half a million tubes, all ours. Watch it- with everyone else
tuned to CNN- Monday, September 22, around 4:30 EST."

unbrandamerica.org: This Ad on CNN
http://unbrandamerica.org/tv/

You can view the ad in Quicktime or Real format here:

unbrandamerica.org: Adbusters' Unbrand America TV Spot 
http://unbrandamerica.org/tv/quicktime.html

Google search strategy:

Google Web Search: "unbrand america" + "cnn"
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22unbrand+america%22+cnn

If this is not the ad you're looking for, or if anything is unclear,
please request clarification; I'll be glad to offer further assistance
before you rate my answer.

Best regards,
pinkfreud