Reading these makes me very happy, I'm so grateful Mr Munroe is still working on them.
I seem to have a category in my brain for cool, creative internet stuff that will last as long as it lasts, but probably won't be replaced by the modern internet.
Anyway.. these days.. xkcd would be starting on Twitter, FB or pictogram. Back then it was blogrolls and Reddit. The medium is the message and the discovery channel is the medium, I think.