According to Compete, Swivel has yet to gain much momentum:
http://siteanalytics.compete.com/swivel.com?metric=uv.
Launched back in Dec 2006, unfortunately, it has still yet to gain heavy traffic...but is nevertheless a really cool graph & analysis site.
For example, if you'd like to compare upload speeds of three wireless providers, you can go to http://www.swivel.com/graphs/spreadsheet/5122288 and view tables/graphs/charts of these.
This is very useful especially in an information overload age. Tools that you can use to slice and dice data into a coherent fashion these days are worth the investigation effort. What's your quirky analytics site du jour?