Flash an update.zip
If you ever see a page telling you to 'apply as update.zip' and you think "What?"
Use this guide!
1.Rename the file to update.zip (Just update in windows)
2.Copy it to the root of your SD card (ie not in any folders)
3.Turn off your phone and turn it back on again holding down power and home
4.Select backup and NAND backup (Not NAND + ext) and wait for it to complete
5.Important - Some ROMs require a wipe of your phone.
Check in the description of your ROM if it requires it.
As a general rule, if you don't wipe and it requires it then you will be stuck at the bootscreen.
6.If you need to wipe, select wipe data/factory reset > wipe data then wipe dalvik-cache (or something similar)
7.Select apply sdcard:update.zip and wait for that to complete
8.Select reboot phone and you should see your new SPL/ROM/Bootscreen ect.
Oficial Rom 2.1:
Optimus 2.1 oficial rom
A88 2.1 oficial rom
Updates for 2.2:
Original recovery (if you need to solve some brick problems):