With great power comes great responsibility, as they say, and many celebrities take their responsibilities very seriously when it comes to acts of charity. Here's Niki May Young's round-up of what some of our favourite figures have been up to this week...

We'll kick-off with one of the most impressive feats shall we? While we're used to being wowed by the frankly stomach-churning efforts of David Walliams, he may have some competition for the 'Toughest-celebrity-fundraiser-of-the-year' title in Yvonne Brown. Never heard of her? Well, that's because she's not technically a celebrity yet, but as only the fifth British woman to attempt to run the Antarctic Ice Marathon near the South Pole, I think she'll be a house-hold name very soon.

Talking of kicking off, the Premier League is playing its part this week, launching its support for the Disasters Emergency Committee East Africa Appeal in the form of 'Tackle Famine' which will see the proceeds of a day of donations at all Premier League matches go to helping the 13 million people in Ethiopia, Kenya and Somalia survive the hunger crisis brought on by severe drought.

ITV television show I'm a Celebrity... Get Me Out of Here has also chosen to support an African cause, announcing its partnership with Malaria No More for the third year running. At least 15p from every phone vote made will go to the charity to help provide mosquito nets for Ghana's 24 million population. 

For those of us growing up in the 80s, you'll likely have a fairly strong affection for the Back to the Future kid himself, Michael J. Fox. Since being diagnosed with Parkinson's early in his career, he has been a strong advocate for sufferers and now holds an annual fundraiser called "A funny thing happened on the way to cure Parkinson's". This year's event on Saturday held a particularly awesome surprise for attendees as Michael rocked out on the guitar in a re-enactment of his Johnny B.Goode performance from the film.

While Michael put his talents to good use, British actress Sienna Miller put her enviable ability to dress well in the spotlight for charity, auctioning off her very own clothes to fund the International Medical Corps. Sienna first started supporting the charity three years ago after hearing the horrific statistic that one woman in the Congo is raped every eight minutes. The International Medical Corps is "the weapon" to battle such violence, she said, and has been a global ambassador and spokeswoman for the charity ever since. There's two days left to grab yourself a (Christmas?) treat from Sienna's eBay auction.

Three celebrities getting in the mood for Christmas (only 40 sleeps to go people!) are Sean Coombes (AKA Puff Daddy/P.Diddy/Puffy/Diddy) Jessica Simpson and Donald Trump, who have put their creativity to the test designing Christmas trees for the Macy's annual charity auction, supporting the Make-A-Wish Foundation. Maintaining a (slightly inappropriate?) tongue-in-cheek approach to the activity, Simpson draped her tree in faux pearls, while Trump added gold bars. Surprisingly Diddy didn't use fur, which has become somewhat of a uniform for the rap star, but rather hung music notes and icicles, to keep in tune with the festive theme.