HydTech

Once I knew what I was doing, everything was simple.
Here are the steps for the G1:

1. Update recovery image (Optional but recommended)

a. download the cyanogenmod recovery image and place it in your SDcard.

b. open up terminal and type
su
mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system
cd /sdcard
flash_image recovery /sdcard/cm-recovery-1.4.img
cat cm-recovery-1.4.img > /system/recovery.img

2. Update cupcake to donut

a. download the 1.6 image here and place it in the sdcard

b. download the mod image here and place it in the sdcard

c. turn off phone

d. boot into recovery mode by pressing home + power

e. from the recovery menu you can select nandroid to backup for safety (optional)

f. alt+ w to wipe (optional)

g. alt + a to apply, first select the 1.6 image and let it complete

h. Do not restart!

i. alt + a to apply, select the cyanogemod image and let it complete

j. reboot

I am so happy, I canceled my T-mobile contract and now I use my G1 to make free VOIP calls using gizmo5 and google voice. I have a wireless connection while I’m at home and at work so thats like 90% of my day. At times when I don’t have a connection, the phone calls get forwarded to my prepaid t-mobile card which is good for 1 year. I paid $100 for it for 1000 minutes.

Things needed before you get started:
1. Sign up for a google voice account and set it up. You can purchase an invite from ioffer.com for like $2.
2. Gizmo5 account. you need to download the desktop client and register. Once you have your sip number (something like 747*******), write it down.
3. SIPdroid app for android
4. Unofficial GV app for android
5. Optional: prepaid sim card

Log in to your google voice account and under settings you can add a phone where you would like your GV number to forward to. Make sure you select type “gizmo” and add the 747 sip number. GV will ask to verify the number so you have to make sure you are signed into your gizmo.

On your android, open sipdroid and enter your account settings.
the server is proxy01.sipphone.com
port is 5060
protocol: UDP is better
You will get a green dot when connected.

Open the GV app (make sure its the unofficial one) and enter your account settings. select calling method as ‘call back’. call back number is your sip number. enter it and enter your pin.
* If you choose the ‘dial out’ method, you will need credits to place a call with gizmo5. the ‘call back’ method tells google voice to dial your number and then once connected with you, call the other number. (This is better because incoming calls are free)

Now you can make and receive calls free while your on Wifi or 3g. In case you want your offline calls forwarded to your prepaid phone, you can select call hunting feature in your gizmo5 account settings.

Enjoy!