Shabbos is Coming, Let's Wear Costumes

Tzipporah Rossman asks a timely question:
Why do we celebrate Purim Katan on Friday if Purim is not allowed to be on Friday and it would get pushed off?
Great question, and I was giving it real consideration about how the problems for Purim would not apply to Purim Katan etc. when I remembered that Purim CAN fall on a Friday, and we celebrate it on that day.  I remember a couple of such instances - though I think there was one more recently, once we spent the seudah at Mrs. Schiowitz's apartment (thanks again), and made it home (one block over) with plenty of time left before Shabbos.  Another time, I remember one of my less pleasant Purims; it was Friday and I was meeting some of my family at a relative in Manhattan for Shabbos, and ended up eating Seudah by myself in my YU dorm room  (highly depressing & not recommended - if anyone has no good plans for seuda please let me know - Purim is not just a day off).  It was there that I heard about the horrific massacre that took place in Israel when Baruch Goldstein opened fire on a Muslim prayer service.
On those types of years, the more interesting phenomena takes place in Yerushalayim, where they have what is called a "Purim Meshulash".  Here's how the OU describes it:

"TRIPLE PURIM"Sometimes Purim falls on a Friday, therefore making the next day, Shabbat, Shushan Purim. However, it is forbidden to read the Megilla on Shabbat, and of course, Shabbat cannot be postponed because of Purim.
For Jerusalem and other walled cities, the procedure is as follows:
“Mikra Megillah” is done on Thursday night and Friday morning, as in the “open” cities; “Matanot La-Evyonim” are given on Friday.
The reading of “Parashat Amalek” and the insertion of “Al HaNisim” into the “Shemoneh Esray” and the “Birchat HaMazon” are done on Shabbat, their regular Purim in ordinary years.
“Seudat Purim” is served and “Mishloach Manot” are exchanged on Sunday, the sixteenth of Adar. 
Thus, the holiday is felt and marked in Jerusalem for three days, and therefore Purim in such a year is called “Purim MeShulash,” Triple Purim.

It's so great to be talking Purim again - I can feel it in the air.