The February 12, 2004 entry from The Oxford English Dictionary's Word of the Day is for the verbal use of the word blog thus:
That earliest citation of the term from the defunct Tasty Bits from the Technology Front is available in their archive.
1999TBTF for 1999-08-30: Aibo Rampant in cistron.lists (Usenet newsgroup) 30 Aug., Blog..to run a Web log. 2000Whole Earth Winter 54/1 To blog is to be part of a community of smart, tech-savvy people who want to be on the forefront of a new literary undertaking. 2001Washington Post (Electronic ed.) 17 May, Journalist Jim Romenesko's clearinghouse for media gossip..showed how a personal blog could go pro when the Poynter Institute hired him..to blog full time.