We hear Yahoo is in talks to buy Tumblr, a blogging startup run by 22-year-old David Karp for "low-to-mid eight figures" — which would translate to a small fortune for the New York entrepreneur. And a quick one, too, without the troubles of figuring out how to make money off of Internet hipsters' self-indulgent ramblings. Karp has toyed with charging users for extra features, but it's not clear th
