I work for the CDN Fastly and we have something very similar to Fast.com.
fastly-debug.com.
The goal of our site is to gather debug information but I use it as a reliable speed-test to a good portion of the internet's websites. I think this is a good tool like fast.com because unlike the 'official' speedtest sites, if you optimize ours or Fast's you're actually making the internet much faster for a lot of sites for users.