There is a new social engineering attack that utilizes the /Launch capability in Acrobat Reader. It is currently being exploited by a particularly nasty trojan named Zeus. It is simple to protect yourself from this exploit some please disable /launch by following the instructions at http://blogs.adobe.com/adobereader/2010/04/didier_stevens_launch_function.html.
For more on Zeus, see this Wikipedia article.
As always; keep your software updated, use anti-malware detection software, use a well-configured firewall when accessing public Internet access point, and use common sense to recognize phishing attempts.