This snippet goes through all the records in my Big Brother Database,
prints out birthdate and a link to the record, and then sorts the
results.

(defun sacha/bbdb-insert-birthdates ()
  "Insert a list of birthdates, sorted by month.
For best effect, dates should be of the form yyyy.mm.dd."
  (insert
   (with-temp-buffer
     (mapcar
      (lambda (rec)
        (when (bbdb-record-getprop rec 'birthdate)
          (insert
           (if (string-match "..\\...$" (bbdb-record-getprop rec 'birthdate))
               (match-string 0 (bbdb-record-getprop rec 'birthdate))
             (bbdb-record-getprop rec 'birthdate))
           " | "
           (planner-make-link
            (concat "bbdb://"
                    (planner-replace-regexp-in-string
                     " " "." (bbdb-record-name rec)))
            (bbdb-record-name rec))
           "\n")))
      (bbdb-records))
     (sort-lines nil (point-min) (point-max))
     (buffer-string)))
  nil)

Random Emacs symbol: find-tag-noselect – Command: Find tag (in current tags table) whose name contains TAGNAME.