Everything that's on the USV "Investments page" should be on the timeline. http://www.usv.com/investments/
There are a few cases in which companies pivoted, so we just listed the new thing (i.e. Hashable to YieldMo)
It has our A round listed, but not the B or C which USV did also - http://www.crunchbase.com/company/twilio
It's comprehensive, but we're only listing the initial investment in each company.
We like to follow-on with each investment, but I couldn't think of a good way to visualize that on a timeline. Any ideas?