Wow, I stumbled upon this site when I went to the Quicksilver 50 mile/50k website to see if there was any new information on next year's event. Once there I saw a link to Realendurance.com made by Gary Wang, an ultramarathoner himself.
It started when he wanted to figure out how many people had ran the American River 50m so he started going through the old records and recording their times and the year that it was completed. Soon enough this lead to imputing just about every endurance race out there, running, cycling, swimming and, of course, triathlons among them. There seem to be a good amount of races not there, at least out here on the West Coast with the Pacific Coast Trails not included, but the list is ongoing.
From one data rat to all the rest, this site could prove interesting if you are an ultrarunner and want a neat, clean searchable database for all ultra runs you have done. Or if you were curious about a particular runner, such as Dean Karnazes or Scott Jurek, you could look them up and see what they have run. Fun site to go through.
Note: The best and easiest way to search events is to go to All Time Lists and chose the state you want to look at, then find the event. Once you click on the event you can see who has completed that event the most all the way down to those that have completed it once. Then you can click on that person's name and it will show all their ultra results, or you can search by name. Once you start searching it is a little tricky to search for someone else as it seems to be stuck on whoever you search for first, even though you are searching a different name. It takes getting used to, but it is fun!