Does Ipad have a usb port?
Does the Ipad2 come with a usb port or a plug in that will allow you to support usb hook up? And does garage band for ipad allow vocal recording or just instrument?
iPad 2, iOS 4.3.3
The iPad does not have a USB port built in. There are some third-party audio devices, though, that use the Dock connector. And of course the iPad 2 has a microphone built in. If you're looking for a serious audio device, the Alesis iO Dock might be worth considering:
Lexicon's Omega is another option, one that apparently works via Apple's Camera Connector Kit:
http://www.lexiconpro.com/static_callout.php?id=85
As to GarageBand, see:
http://www.maclife.com/article/features/garageband_ipad_2_what_we_know
Regards.