By default android multitasks.
Could you clarify?
Until the oom killer kicks in, or you manually force close apps, they usually stay running in the background until reboot.
If you're running ics or later, hold down the home button to see what all is running. Swipe em away to kill em.
even Froyo does that.Sorry for the vagueness, I meant multitasking as in multiple windows opened at once.
even Froyo does that.
to re-open an app in the state you exited it from, long-press home button, select the app.
it'll reopen where it was when you exited it.