I first came across his work at Tin House, where O'Hora contributed the banner illustration for the site's blog. Here are some of his other illustrations, which I think combine whimsy with drudgery quite nicely.
His work reminds me a litte of Richard Scarry and a little of Wes Anderson. Check out more of O'Hora's work at his website, Fuzzytown, where you can also find links to his blogs.
Images from Fuzzytown