I should mention a fairly big Windows vulnerability (which involves active scripting). Apparently there are proof-of-concept exploits circulating that do innocent things like open up the calculator. Unfortunately, once exploits are out that can do this, it’s trivial for them to do worse. The bottom line is, be careful what sites you visit, beware of “driveby downloads” using this tactic consider alternative browsers until you’re patched. (Although in reality, with IE’s integration in Windows, it’s hard to be completely safe this way with other apps using IE to view html objects….)