The shocking images, videos and reports coming out of Japan in the aftermath of today's tsunami and earthquake leave a lot of us thinking "What can I do to help if I live so far away?" Writing a sympathetic Facebook status update or Tweet is a nice gesture, but it isn't exactly proactive. Thankfully, you can help--even if you're thousands of miles away. Relief efforts for Japan are already starting to pop up in the form of mobile donations and web forms through many well-known charitable and disaster relief organizations. But be aware: While mobile donations are certainly the quickest way to donate, they are not always the most effective.

Donating by cell phone is incredibly quick and easy (and takes about as much time as a Facebook status update). You just text a particular word or a number to a specific phone number, and a set amount is charged to your phone bill. Your carrier then delivers the funds to the charity. The mobile donation approach has been around for a couple of years, but it didn't really catch on until the 2010 Haiti earthquake. The American Red Cross's Haiti Relief and Development Fund, the most successful mobile campaign to date, raised more than $32 million within a month after the disaster.

Before you start texting away, though, make sure that you're donating to a legit nonprofit organization. If you're unsure about a charity, you can look it up on a watchdog site such as Charity Watch. Be wary of charities you've never heard of or organizations that contact you directly to get you to donate via text. Stick to the big-name charities, and you should be okay.

The Federal Trade Commission also advises prospective donors to give directly to a charity rather than to a group that solicits contributions on a charity's behalf. A group advocating for the American Red Cross, for example, will take a portion of the proceeds to cover its costs, leaving less of your donation for people in need.

The biggest problem with mobile donations, though, isn't where the money is going, but how long it will take to get there. It might take only a few seconds for a donor to text "JAPAN," yet the contribution might not reach the targeted relief agencies for a few months. Some carriers, such as Sprint, expedited their subscribers' donations to Haiti relief organizations. Normally, however, it takes roughly 30 to 60 days for the carriers to transfer donated funds to an agency.

In any event, mobile donations can do only so much. Carriers may impose limits on the amount and the number of times you can donate. For example, during the Haiti earthquake crisis, AT&T imposed monthly maximums of five donations of $5 or three donations of $10. If you're looking to make an impact, the best way is via a one-time lump-sum contribution to the charity's Website.

Donate to Japan:

Red Cross: Text REDCROSS to 90999 to donate $10 from your phone. This will donate to the general Red Cross Disaster Relief Fund, so if you want to ensure that it goes to Japan you'll have to donate from their Web site.

Salvation Army: To contribute to earthquake relief, text 'JAPAN' or 'QUAKE' to 80888 to make a $10 donation or visit SalvationArmyUSA.org.

Convoy of Hope : A non-profit for disaster relief efforts. You can donate either online or via text message by texting TSUNAMI to 50555.