If you cannot set up Gmail with the Gmail short cut in add account.
You might want to set up Gmail as other.
First off all make sure that you have enabled pop on your Gmail account.
http://mail.google.com/support/bin/answer.py?answer=13273&topic=1556
Then on your iphone, go to settings>mail>add account
choose other
then enter needed information
Server Information
Incoming mail server (POP3): pop.gmail.com
Outgoing mail server (SMTP): smtp.gmail.com
Login Information
User Name: Enter your Gmail username (including @gmail.com)
Password: Enter your Gmail password
Once the account sets up, you can go back into the account settings>advanced and turn ssl off.
Hope this helps