ripping cds with cddb look-up

Use ripit's --save option for creating a config file ~/.ripit/config.

ripit -t http -S standard -D '"$year - $album"' -T '"$tracknum - $artist - $trackname"' --playlist 0 --core 4 -o .

limit lftp upload rate

For 10 Kb/s:
set net:limit-rate 0:10240

convert / resize many images using 4 threads at a time

mkdir small
for i in *.JPG; do while [ `ps --no-headers -C convert | wc -l` == "4" ]; do sleep 1; done; convert -quality 95% -resize 30% $i small/$i & done