This just in from one of our regular tipsters here at Mashable - thousands of popular blogs are down tonight, from PerezHilton, ValleyWag, Consumerist all the way on down to LouisGray.com. Why? Because they use SiteMeter, a popular free traffic metrics utility.
As of this moment, there hasn't been any official statement from SiteMeter via their blog nor by their support personnel regarding the outage, but their main site still functions smoothly. Still, for all sites running the JavaScript based counter, when users come to the site using Internet Explorer 7, the page attempts to load, and then pops up a dialog box that says "Internet Explorer cannot open the Internet site
Clicking OK on the box will return the standard error screen in Internet Explorer when a site can't be reached for connectivity issues.
Firefox users appear to be completely unaffected.
Update #1: According to Mashable Reader Luigi, it appears that that users of IE6.x are similiarly affected. Also, it looks like Duncan Riley might've had the same tipster we did, and Duncan was quicker on the keyboard getting the news out.