you can do a custom search and SAVE the PNG image

http://www.google.com/trends/viz?q=google&date=all&geo=all&graph=weekly_img

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or you could TWEAK the Search

http://www.google.com/trends/viz?q=google&date=2006&geo=all&graph=weekly_img

you can also tweak the "DATE" attribute

the 2006 limited the search to this year

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http://www.google.com/trends/viz?q=google&date=2006&geo=us&graph=weekly_img

the GEO code could be replace by a country code to limit it to that country eg US