The window cling itself was designed to be the largest size that fit in a standard mailing envelope so as to avoid excess postage charges.

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User fees are charges for items like postage stamps, Medicare premiums, veterans' life insurance policies and electricity rates for power supplied by federal agencies such as the Tennessee Valley Authority.

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User fees are charges for items like postage stamps, Medicare premiums, veterans' life insurance policies and electricity rates for power supplied by federal agencies such as the Tennessee Valley Authority (nyse: TVC - news - people ).

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Traditionally, postage stamps and Medicare payments make up about half of all user charges.

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One experimental propulsion system embeds thousands of tiny explosive charges in a piece of silicon the size of a postage stamp.

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