To configure Gmail on an Apple device (e.g. iPhone, iPad, iPod Touch), using Safari browser:

1. Make sure you've enabled 'IMAP' in your Gmail settings
2. Open the Settings app on your device
3. Tap Mail, Contacts, Calenders
4. Tap Add Account
5. Tap Gmail
6. Enter you account information, being sure to use your full Gmail address, uncluding @gmail.com
7. Tap Next
8. Tap Save

See full instructions on the Goggle Mail Help website, at : https://mail.google.com/support/bin/answer.py?answer=77702