Eddie Izzard photographs himself running with an English flag. Photo: eddieizzard, twitter.com

We all run for our own reasons, but lately, more and more people are running to support a cause. Plenty of celebs have gotten in on the act, and currently, actor, comedian and (warning: following link has video with graphic language) executive transvestite Eddie Izzard is running around the entire United Kingdom to raise money for Comic Relief.

Comic Relief is a charity that envisions "a just world free from poverty," and works toward that goal using those in the entertainment industry to encourage folks who otherwise might not volunteer and work and give for charity. Izzard is harnessing the power of social media to get people to donate to his cause -- if you follow him on Twitter, you'll get constant updates, comments and pictures (like the one to the right).

Of course, regular people take on incredible challenges for charity, too. Katie Visco's run across the United States is an effort to raise funds for Girls on the Run, and Nick Irons swam the Mississippi and biked 10,000 miles for his father, who has multiple sclerosis.

Ideally, hearing stories like these will motivate you to reach in your wallet and help out the charity of your choice. But, does it make you want to lace up your shoes and challenge yourself physically, too? Are you inspired to do an event for charity yourself?