Flite installed fine on my n810 and works with the -t option but not the -f option. When it tries to read a file it just makes ungodly static (I didn't know that quiet little speaker could make so much noise!). I am typing
flite -f textfile
or
flite -f /home/user/textfile
It reads text from the command line just fine.

UPDATE

When I tried
flite -f textfile -pw
it read the file with several voices reading different parts of the file at once. ODD.