It's very hard for me, as a programmer, to take this idea of a singularity seriously. I know how all of the technologies that Kurzweil is banking on work at a very low level and I call bullshit that this is ever going to happen. It would require a type of software that simply does not exist yet, something akin to a self-programming software, and we are so far away from that that it might as well be cold fusion.
I think it's much more valid to call the "singularity" the point in time when technological expansion started occurring at an exponential rate. Thus I would put the singularity at about 200 years in the past, right around the time the spinning jenny was invented, and right before the industrial revolution. Now there's a point in time that I can point to and say "something meaningful happened". This is complete pie in the sky stuff, and I'm extremely cynical that it's not just something that Kurzweil talks about to sell books and conference tickets.