What futures are already here?
I find this quote to be a more reliable guide to the future than most predictions.
In 2000, Google was already two years old. Wireless was still pretty new, but every geek gathering just had to have it. Little digital cameras that you could attach to a phone were interesting curiosities. Phones that did email and web browsing existed but were super expensive and clunky.
In the other thread with predictions for the decade, almost all of them boil down to whatever's hot in 2009, only more so.
I'd like to ask the HN community to instead think of the really niche, expensive, geeky, "the mainstream will never get this" aspects of their lives right now. Stuff they find really useful, or just cool. And then consider if there's any upper bound to much they could scale up, or how easy these technologies could be made for others.
Now those would be predictions....