Extremely beautiful woman Megan Fox appeared in season one, playing the role of an extremely beautiful woman.
[subheader:list:2 & 3]Sean Penn & Elvis Costello[/subheader]
Cool guys Penn and Costello played themselves in the season 2 opener, smoking cigars and drinking whisky and being cool.
Simple, Southern girl Miley, played the role of Missi, a simple, Southern girl.
Estevez played the character of of a hard partying, womanising man. He probably picked up some good tips for the role from his brother, Charlie Sheen.
Charlie Sheen's dad played the role of a father who was angry at Charlie, so we imagine he'd had a fair bit of practice before getting the role.
Before divorcing Sheen for his wild ways, Richards played the role of Lisa in Two and a Half Men, who dumped Charlie for his wild ways.
Not having learned anything from Sheen, Ashton Kutcher also got his wife involved in the show. They are however, yet to divorce.
When Kutcher said "Shut up, Bolton!" to Michael Bolton in season 10, he was just saying what most ordinary people have dreamed of saying for years.
[subheader:list:10]Eddie Van Halen[/subheader]
In an effort to calm down Charlie Sheen's wild ways, Eddie from hard rockers Van Halen was bought in.
With Ashton Kutcher being no stranger to an older lady, it was no surprse when his charcter ended up sleeping with Hilary Duff's character's grandmother.
Charlie met his match with Hatcher's charcter Liz, a sleazy adulterous woman.
Having already given roles to all the women in California, Steven Tyler was deemed the next best option for this role is Season 4.
[subheader:list:14 & 15]Christian Slater & Arnold Schwarzenegger[/subheader]
If you want to catch Slater and Arnie's cameos then make sure you watch the last ever episode of Two and Half Men this Easter Monday at 9pm.