Go there! http://teststackoverflow.com/
We are running performance tests analyzing changes to our global network. It is not malicious, we're just collecting performance metrics as we make major changes to our infrastructure. We want to ensure performance gets better, not worse, as we make changes.
Edit: I forgot to mention the separate domain is temporary. Part of the changes we're evaluating are geo-located DNS servers, which means we need another top level domain since we have to hand off the SOA record for a 100% valid test. In the future we will continue collecting timings on 0.1% - 1% of page loads, but it will not be a separate domain or