These stamps have at least one flat side. Special stamps are the extra stamps the post office prints each year. The Love stamps and the Christmas stamps are special stamps. Commemorative stamps are usually bigger and more colorfull than the definative stamps. The stamps often honor people or special events.
Commemoratives are only available for a short time and only a limited number are printed.
You sure can. You can check out your local phone book. Another way to buy stamps is to look in magazines like Linns Stamp News You can even go to Yahoo and search on the word 'stamps'.