If you’re using the Opera webbrowser, now would be a good time to upgrade to the latest (9.60) release; earlier versions are vulnerable to an “extremely severe” bug that could allow an attacker to run code on your computer:

If a malicious page redirects Opera to a specially crafted address (URL), it can cause Opera to crash. Given sufficient address content, the crash could cause execution of code controlled by the attacking page.

If that’s not enough reason to upgrade, there’s also a “highly severe” bug that might disclose sensitive information on your PC.