Create a lot of snaps, serially or in parallel:
snaps-create.sh
======================
#!/bin/bash
set -x
VOLUME=$1
NUMSNAPS=$2
PARALLEL=$3
echo Creating $NUMSNAPS snapshots on volume $VOLUME
if [ -n "$PARALLEL" ]; then
  echo Will run commands in parallel
else
  echo Will run commands serially
fi
for ((i=1; i<=$NUMSNAPS; i++)) ; do
  echo "Creating snapshot $i"
  COMMAND="euca-create-snapshot $VOLUME"
  if [ -n "$PARALLEL" ]; then
    $COMMAND &
  else
    $COMMAND
  fi
done
======================

Example usage, creating 10 snapshots on each of 3 volumes already created, all in parallel (remove 'y' params to do serially instead):
# snaps-create.sh vol-e7d3f9fa 10 y & snaps-create.sh vol-1c77102b 10 y & snaps-create.sh vol-3f61d26a 10 y

Deleting all snapshots for all volumes: (careful!)
snaps-delete.sh
======================
#!/bin/bash
#set -x
while true ; do
  snapshot=$(euca-describe-snapshots | head -1 | awk '{ print $2 }' | tr -d "\n")
  if [ -z "$snapshot" ] ; then break; fi
  echo "Deleting snapshot $snapshot"
  euca-delete-snapshot $snapshot
done
======================