echo "Enter the item separated by colons"
read col
i=1
while [ 1 ]
do
s=`echo $col | cut -d ":" -f $i`
if [ ! $s ]
then
exit
else
echo $s
i=`expr $i + 1`
fi
done

OUTPUT
***********
    [04MCA58@LINTEL 04MCA58]$ sh colon.sh
Enter the item separated by colons
abc:xyfds:sdfjek
abc
xyfds
sdfjek