How to enable real text prediction for android / stock keyboard on LG optimus one?
I found this review of the LG Optimus One which includes this quote:


  The standard Android keyboard’s text
  prediction is disabled; it doesn’t
  seem to have access to the system’s
  language dictionaries.  So if you want
  word prediction, the LG keyboard it
  is.


Looks like you're going to have to go with a third-party app solution or flash a new ROM to your phone.