I personally use the Chrome Nanny extension to block certain websites during specified hours. This goal-oriented approach is interesting though, as it seems to get at the core issue: "to create more than you consume".
I think that's a good observation about how this approach differs: it's not just a technical hack, but a behavioral one as well--the user experience with the tool is to simply do the warmups that they want to be doing anyway. I like that a lot, but it still feels like the tool is missing something to really successfully accomplish that.