I’ve had a 12″ iBook G4 since 2005 and it’s still my favorite notebook for browsing the internet, writing letters, and even reading pdf’s. It’s very lightweight and I consider the screen the perfect size. It’s held up very well. One of the keys has a hairline crack and one of the rubber feet on the bottom fell off but I clean it every month or so and it still looks almost new.
My only criticism is that it gets a little warm so I keep it on top of a clipboard when holding it in my lap. No viruses, no crashes, no worries.
When netbooks started becoming popular a couple of years ago, I had to laugh because I already have a lightweight, handy netbook. In fact, I’m using it right now to write this review. Given a choice between a new Asus or Dell netbook or a used iBook G4 for the same price, I would take the G4 without thinking about it for a second.