Checks your Facebook friends and records the people that have removed you as a friend since the last check. Technically this is against the API's Terms of Service, so let's just call this a proof of concept.

compare.py

import sys
import json

def fbquery(token, query):
    from urllib import urlencode
    from urllib2 import urlopen
    from re import sub

    query = sub('\ {2,}', ' ', query)
    url = 'https://api.facebook.com/method/fql.query?' + urlencode({'query': query, 'access_token': token, 'format': 'json'})
    return json.loads(urlopen(url).read())

def load_file(f):
    from os.path import exists
    content = None

    if exists(f):
        with file(f, 'r') as fh:
            content = json.loads(''.join(fh.readlines()))

    return extract_data(content)

def extract_data(data):
    friends = []

    if data != None:
        for friend in data:
            friends.append(friend['name'])

    return friends

def main():
    if len(sys.argv) != 3:
        return 'Please specify the cached file and then the access token'

    cached = load_file(sys.argv[1])
    token = sys.argv[2]

    data = fbquery(token, """SELECT uid, name
                             FROM user
                             WHERE uid IN (
                                 SELECT uid2
                                 FROM friend
                                 WHERE uid1 = me()
                             )""")
    new = extract_data(data)

    for name in cached:
        if not name in new:
            print 'Peace, %s' % name

    with file(sys.argv[1], 'w') as fh:
        fh.write(json.dumps(data))

if __name__ == '__main__':
    sys.exit(main())