fatalsaint: still, the OP seemed to say the N1 didn't multitask. Hard to say that up to 6 isn't "multi"
When you open an application, its screens open, but the previous application doesn't stop; it keeps on running: playing music, rendering a webpage, and so on. You can quickly switch among your open applications, to work with several at once. Android and each application work together to ensure that applications you aren't using don't consume resources unnecessarily, stopping and starting them as needed (you don't need to quit an application when you aren't using it).