In his 80s columns he wrote (roughly, by my memory) that by the turn of the millennium you'd be able to go to your computer and ask any question with a publically known answer, and get it back right away. I thought that was ridiculous, and today you can quibble, but basically yes, you can, and he was right on the money on the timing. That was an audacious prediction back then.
He influenced me the most by his columns on space development (A Step Farther Out, and a couple of anthologies The Endless Frontier). I don't clearly remember what was in them, but there was a kind of can-do attitude about developing technological civilization in a strategic way that seems more in tune with the 60s than anything happening now.