Why do you ask, do you have either? Or are you deciding what to get? I had an iphone for 2 years and decided to try something new not knowing what I was doing. I recently got a nexus s as an upgrade, tried it for a month and it's now in it's box as a spare phone.

usb host mode
preenv, webos games on n900
cutetube, youtube video downloader
great community and support (not from nokia)

It is a computer not a phone

And no, a jailbroken iphone will only install software written for iphone but not approved by apple.

I haven't even started to list what this thing can do

Hope this helps.