Make a nandroid before anything. Since you already have voice i just got the data stuff from 2 separate places for the Droid and other android phones. Cant hurt to try though. I don't have an extra Optimus or Cricket so i can't try this stuff. And you do have data added to your account already right?
if you have QPST open it on the com port 10 read your settings. under MIP mip2,,PPP(Um,AN...etc it should say
6155555551@mycricket.com etc in the right columns....in the bottom box password may need to be written to phone, just type in cricket for both Um and An, cricket is the password.
Also select mobile ip+simple ip under MiP tab
select write to phone
Open the Voice Dialer on the phone and say “Open APNs” and click open.
If you can't get this to open then get a program from the market called APN backup and restore. Open this and click backup. This will create an xml file on your sd card in the apn backup restore folder. mount your phone as usb .(save a copy of the xml just in case on your pc.) open the xml on the sd card with notepad (notepad ++) on a pc and change everything to what is below. Click save and then unmount from usb. Then on your phone open apn backup & restore again. Click delete APNs. Then restore APNs. Then continue to next directions.
Click on the APN and edit everything to match below:
Name - Cricket
APN internet
Proxy wap.mycricket.com:8080
Port 8080
Username yourphonenumber@mycricket.com
Password cricket
Server wap.mycricket.com
MMSC http://mms.mycricket.com/servlets/mms
MMS Proxy wap.mycricket.com
MMS Port 8080
MCC 310
MNC 004
Authentication Type PAP or CHAP
APN type <Not set>
Now click the menu button and click Save.
Go to
XDA
[Follow directions under requirements]and get the Cricket files then flash them in recovery. The files contain some scripts and the files required to forward connections through the proxy. Dont forget to get autostart.
Reboot phone and see if data works.
If it works we can write it up cleaner and give credit to those various people so that others may benefit. If it doesn't work you are no worse off than before.
PS i said make backups so im not responsible for anything.