Aon
Maj. Margaret "Hotlips" Houlihan was played by Loretta Swit, born November 4th, 1937, while Margaret was born in the mid 1920s.

Dó
The site's name comes from the episode "The Winchester Tapes" in Season 6. Winchester was recording himself for his family back home and mentioned that there was "a head nurse, who's part Seductress and part Attila the Hun" and you see his little smile! He goes on to describe an incident between himself and Margaret, found here: Quotes.

Trí
Margaret's nickname 'Hot Lips' came from the movie. Radar [Gary Burghoff - only character from the movie] slid a mike into her tent when she and Frank Burns were together, and she asked him to 'kiss her hot lips'. Everybody heard them on the camp speakers and from then on the name stuck, and it carried over to the TV series as well.

Ceathair
Margaret wasn't a natural blonde, as she liked people to think. She dyed her hair in the secrecy of her tent, and was caught quite a few times by people coming in unannounced. She even hid it from Frank.

Cúig
Margaret had relationships/romances with many different men, even it was only a kiss. These included:
Frank: Relationship for the first four seasons and presumably the first episode of Season 5.
Hawkeye: Kissed and comments [see Comrade In Arms, Season 6]
Trapper: Kisses and comments [see Check-Up and Bombed, Season 3]
Henry: Kiss in the last episode of Season 3
Donald: Fiancé/Husband for just over two seasons [5 - 7]
Charles: Comments and [Say No More, Season 11]
Scully: [A Night At Rosie's, Season 7] [Guerilla My Dreams, Stars and Stripes, Season 8]
Numerous higher-ranking officers
Ignazio de Simone [Cementing Relationships, Season 9]: The jilted Italian feels Margaret is the perfect woman for him.
Per Johannsen [UN, the Night and the Music, Season 11]: Three UN representatives arrived promoting...I dunno, good relations, and Margaret fell for the Swede, who spent a night with her in her tent.

Trapp and Kling's Guide to M*A*S*H has a lovely wee bit on 'Margaret's Men' :)

Sé
Major Margaret Houlihan lasted through all eleven seasons, one of only 4 characters to do so. Wasn't she brilliant?! *L*
[Others were Hawkeye, Fr. Mulcahy and Klinger]

Seacht
The first sign of trouble in Margaret's marriage comes in "In Love and War" in season 6, only 7 episodes after she marries. A new nurse describes how she spent her remaining time in Tokyo before her transfer with a Lieutenant Colonel called Donald...

Ocht
Season 6: What's Up, Doc? was the only episode where Margaret thought she was pregnant, and the idea of a little baby in the camp cheered up the other officers no end! Hawkeye and Margaret had to remove the ovaries from Radar's rabbit, Fluffy, for a test, but what was the result?? :P