I've been driving my new xB for about 100 miles so far. Is there any particular way I'm supposed to rive it for the first 1000 miles, to break the engine in?

:? You should know by now to use the search.
http://www.scionlife.com/forums/viewtopic.php?p=249704&highlight=break+period#249704

http://www.scionlife.com/forums/viewtopic.php?t=16573&highlight=break+period

http://www.scionlife.com/forums/viewtopic.php?p=166909&highlight=break+period#166909

will be lizocked!

I'll check those out, thanks.