Quick and dirty script to get multiple types of checksum for a file.

get-checksums.sh

#!/bin/bash

dir=$(mktemp -d)

cmd="cat \"${1}\" | tee"
shift

sums="md5 sha1"
if [ ! -z "${*}" ] ; then
	sums="${@}"
fi

for i in ${sums} ; do
	cmd="${cmd} >(${i}sum - > \"${dir}/${i}\")"
done

bash -c "${cmd} > /dev/null"

pushd "${dir}" > /dev/null
for i in ${sums} ; do
	echo -ne "${i}\t: "
	awk '{ print $1 }' < $i
done
popd > /dev/null

rm -r "${dir}"

I wrote this for the purpose of piping it into zenity in a Thunar action:
get-checksums.sh %f | zenity --text-info --width=500