Upverter has all the standard trappings of proprietary SaaS businesses (see [1] for a flame-baity editorial).
I think KiCAD is awesome but the learning curve is steep, the interface is a little dated and it's hard to get started and/or share your schematics easily (e.g. online). This was one of the reasons why I wanted to like Upverter so much but the fact they were just another closed source business was a no-go for me.
Anyway, I created MeowCAD as an alternative [2]. It's free and open source [3] allowing you to do circuit design in your browser.
Sorry for the shameless self promotion.
[1] http://dangerousprototypes.com/blog/2011/09/21/editorial-upv...