Text-to-speech bash script using libttspico. Encodes to ogg and/or mp3. Decent quality. Got me through my literature class.

tts.sh

#!/bin/bash

#
# Takes a text file and makes an audiobook for it. 
# 
# Specifically:
#   Converts a single text file to multiple ogg and/or mp3 files.
#
# Requires:
#   libttspico-data libttspico0 libttspico-utils
#   libttspico-dev lame vorbis-tools
#
# Use:
#   Say you have a book in plain-text format called "book.txt".
#   $ bash ~/Apps/bash/tts.sh book.txt
#

# Process commandline arguments
while getopts "f:sh" opt
do
  case $opt in
    f)
      format="$OPTARG"
    ;;
    s)
      single=1
    ;;
    h)
      echo "Usage: `basename $0` [OPTION]... FILE
Perform text-to-speech on FILE.

  -f  specify output format
        if unspecified, outputs both formats
        possible arguments:
          ogg
          mp3
  -s  single audio file
        encode as 'filename.ogg', rather than
        the default 'filename-part-i-of-n.ogg'
  -h  display help and exit

Examples:
  `basename $0` book.txt
  `basename $0` -f ogg -s snippet.txt"
      exit 1
    ;;
  esac
done
shift $(($OPTIND - 1))

file="$1"                                     # book.txt
filename="${file%.*}"                         # book
workingDir=".$filename-tts"                   # .book-tts
filePartPrefix="$filename-part-"              # book-part-
filePartOutput="$workingDir/$filePartPrefix"  # .book-tts/book-part-

# Determine how many parts there will be
bytes=$(wc -c < $file)
parts=$(( bytes/32000 ))
if [ $(( bytes%32000 )) -gt 0 ]
then
  ((parts++))
fi

if [ -n "$single" ] && [ "$parts" -gt 1 ]
then
  echo "Error: More than 1 part.
Reduce filesize to <= 32000 bytes or do not specify the '-s' flag."
  exit 1
fi

# Make a temporary working directory
mkdir "$workingDir"

# Split the file into chunks that pico2wave can manage
# (the maximum bytes allowed is around 2^15)
echo "Splitting file into $parts parts ..."
split --bytes=32000 --suffix-length=4 --numeric-suffixes "$file" "$filePartOutput"
for aFile in $(ls $filePartOutput*)
do
  mv $aFile ${aFile}.txt
done

# Perform text-to-speech using pico2wave
echo "Performing text-to-speech ..."
i=1
for part in $filePartOutput[0-9]*.txt
do
  if [ -n "$single" ]
  then
    ttsFilename="$filename"
  else
    ttsFilename="$filePartPrefix$i-of-$parts"
  fi
  ttsWav="$workingDir/$ttsFilename.wav"
  
  # Perform text-to-speech for this part
  echo "TTSing part $i of $parts ... ($part)"
  fileContents=$(<"$part")
  pico2wave -l=en-US -w="$ttsWav" "$fileContents"
  
  # Encode audio to distributable formats
  # Encode to both if '-f' flag is unspecified
  # If '-f' flag is specified, only encode to the argument format
  if [ -z "$format" -o "$format" == "ogg" ]
  then
    echo "Encoding to ogg ..."
    oggenc "$ttsWav" --output="$ttsFilename.ogg"
  fi
  if [ -z "$format" -o "$format" == "mp3" ]
  then
    echo "Encoding to mp3 ..."
    lame -V 8 --vbr-new -h -q 0 "$ttsWav" "$ttsFilename.mp3"
  fi
  
  ((i++))
done

# Clean up
rm -rf $workingDir

echo "TTS complete."

I write Google TTS version.
Check it here: Simple Text To Speech (Bash Script - Google TTS)