Twitter continues to see explosive growth – according to comScore, Web site traffic to Twitter.com accelerated 131 percent in March while the Wall Street Journal (Twitter handle @wsj) reported on May 26 that Twitter now has more than 32 million users. Corporate brands, celebrities and political leaders are all using Twitter to communicate with one another and share information.

Many organizations and philanthropists are even using Twitter to inspire and motivate their followers to take action by donating and volunteering their time. A May 19 article on TechCrunch (@techcrunch) reveals how Queen Rania of Jordan (@queenrania) leverages Twitter to inspire and encourage social change.

Queen Rania tells TechCrunch, “Twitter’s a great way to tell people across the world what I care about and, hopefully, motivate them to join me in furthering my causes. It’s also a fantastic medium to hear the ideas and opinions of people I might not otherwise get to meet.”

The Bill and Melinda Gates Foundation (@gatesfoundation) also tweets frequently to build awareness of issues such as global healthcare and education. For example, in the days leading up to World Malaria Day on April 25, the Bill and Melinda Gates Foundation posted tweets focusing on the world progress against this disease. The organization also posted tweets encouraging followers to join in the World Malaria Day discussion on Facebook which offered information on Malaria Day activities.

Actor Ashton Kutcher (@aplusk) furthered support for World Malaria Day when he challenged CNN’s Ted Turner in a race to secure one million followers on Twitter. Kutcher agreed to donate 10,000 mosquito nets to Malaria No More, a charity he asked followers to support. True to his word, Kutcher donated the mosquito nets after winning the race in on April. He now has close to two million followers.

Another example of how Twitter has been used for social causes is GlobalGiving (@globalgiving), an online marketplace that connects individuals to causes and countries. GlobalGiving tweets daily to encourage donations and action for worthy causes. Tweets direct followers to the GlobalGiving Web site where people can donate to a variety of causes ranging from women’s domestic violence, education, healthcare and relief efforts for displaced families in Pakistan.

Communiqué PR (@communiquepr) client Seattle Children’s PlayGarden (@playgarden) is also using Twitter and Facebook for its fundraising. Click here to read how Seattle Children’s PlayGarden is leveraging social media to raise funds for children with special needs.

These are just a few examples of how Twitter can be an instrument for social change. In the coming year, I suspect more organizations will turn to Twitter to raise awareness for unique causes, programs and fundraising campaigns.