Google Android 2.3.4 Users Guide - Manual (Page 208)

Google Talk 208
AUG-2.3.4-106 Android User’s Guide
Set whether you sign into Google Talk automatically
1 In the Friends list, press Menu and then touch Settings.
2 Check or uncheck Automatically sign-in.
When Automatically sign-in is checked, you are signed into Google Talk when
you turn on your phone.
Signing in and out of Google Talk is described in “Signing in and opening your
Friends list” on page 196.