According to Wikipedia, the term “weblog” (i.e a web log) was coined by Jorn Barger on 17 December, 1997. The short form, “blog”, was coined by Peter Merholz, who jokingly broke the word weblog into the phrase we blog in the sidebar of his blog in April or May, 1999.

In other words, we’re hard at work and haven’t got time to blog right now.