This is all those who has unlocked their iPhone, have an old AT&T sim and no EDGE.
1. don't bother looking for than damn EDGE setting. You have to go old school and edit a file.
2. ssh into your iphone
3. cd /var/root/Library/Preferences/SystemConfiguration
3.5. cp preferences.plist preferences.plist.orig
4. vi preferences.plist
5. search for "cingular"
6. This should bring you to a code chunk that has the following
<key>apn</key>
<string>wap.cingular</string>
<key>password</key>
<string>CINGULAR1</string>
<key>username</key>
<string>
[email protected]</string>
7. replace wap.cingular with proxy. Delete CINGULAR1 and
[email protected]. So it looks like the following
<key>apn</key>
<string>proxy</string>
<key>password</key>
<string></string>
<key>username</key>
<string></string>
8. Save. Exit you session. Reboot your iphone.
9. Enjoy edge on your old AT&T plan
Your mileage may vary
I don't know is SMS works. why?. I'm tired and I'm going to bed.
You can do any of the steps if you don't have an unlocked phone and at the very least have ssh installed on the iphone.
Cheers y'all