I hate to damper anyone's enthusiasm, but isn't "finding" graphics/smilies a little too much like that guy who recently "found" some SEO articles for his web site?
Whether it's a tiny smilie, an intricate page design, or a 2,000 word article,
someone invested time and talent in creating it. If it "appears" to be in the public domain, that usually just means the last person to steal it didn't put their own name on it. Does anyone really want to be responsible for perpetuating the complete lack of disregard for intellectual property rights that has characterized the Internet for the past decade?