Create various sizes of iPhone app icons with sips command.

makeIcons.sh

#!/bin/sh
if [ $# -lt 1 ]; then
        echo "Uage: $0 ImageFileName"
        exit 1
fi
FILE=$1
BASENAME=${FILE%.*}
EXT=${FILE##*.}
DIR=icons

for size in 180 120 80 60 40 87 58 29
do
        sips -z $size $size $FILE --out $DIR/$BASENAME-$size.$EXT
done