You can not even closely switch as fast between apps. Do this: open call log, to browser windows, notepad, music player, new sms, and oooh... say... gallery. Now switch fom call log to first browser window, hit refresh, then to notepad, check the website refreshed, to music player, check browser window 1 again, to new sms, then gallery, go back to call log, go into second browser window and back to new sms.