Setup gmail on my samsung i600

i had the same problem.....i atleast hd to set up an account on my computer first, then i was able to access it from my phone. My setting for att data are as follows go to start, then to settings, next to more at the bottom, then to connections, then to proxy, then to att wap, next make sure you have connects from: wap network then have connects to: the internet and have the type: http.....i had no user name or password in the fields below.
Like i said before these are the options i have set for the att data plan.If your using a wireless router as a accsess point i dont have a configuration for that. Hope this helps

I can access gmail on my phone; it's fairly straightforward: - unlock the keypad - hit the 'envelope' button at the bottom right to go into 'Messaging' - select the bottom item: "New Acccount" - choose "Other (POP3/IMAP)" from the e-mail provider list and hit Next - Enter your name and email address, then hit Next (leave the "Automatic setup" checkbox ticked; it makes no difference) - hit Next again to skip the automatic configuration - enter your gmail username (with the @gmail.com bit; I like to use the recent:myusername@gmail.com to download only the most recent emails) and password. Leave Domain (if necessary) blank and hit Next - choose server type "POP3", account name "Gmail" and select whatever network (WAP Gateway or Internet) you want to use, depending on how you want to connect - Enter the following - - Incoming Server: pop.googlemail.com - - Require SSL connection should be checked (ticked) - - Outgoing Server: smtp.googlemail.com - - Outgoing server requires authentication should be checked - - Outgoing server configuration: - - - Use different user name for outgoing server (if you've used the recent: username for downloading email) - - - Enter your gmail username@gmail.com - - - Enter your password - - - Leave domain blank and check "save password"  - - - check "Require SSL connection" - - - then click Done - - Select however many day's worth of emails you want to download and click Next - - Select "Never" to connect automatically if you aren't on an unlimited data tariff! - Click Next then Finish.
Hope this works!