I bought an Acer Aspire One D250 netbook last month... And Am glad to tell you that it was working absolutely fine till 2 days back... Its a good machine.. portable enough.. decent keyboard size.... The factor that will discourage you from buying it will be the plasticky feel of the thing..
Also it has a degraded battery life... So can t count on it when you hit the outdoors.. Better to lug a charger around all the time.. Also The Acer Aspire One has really weak speakers.. so it wont help to view a movie or listen to music if you do not have a good pair of earphones.. . All in all a cheap netbook with cheaper features.. Better to spend a bit more and go for some other brands like Asus, Samsung or HP.. At least you get peace of mind that the device is not gonna make your life difficult...:(