Trying to raise money can be very difficult in a poor economy, but there are always people willing to be charitable. You just have to find them, and become their charity of choice.
To raise money for your cause, start with a web site that tells the world what you're all about. It doesn't have to be high tech, but it should include your purpose, pictures, contact information, and most importantly, a way to contribute online. It's very simple to set up a paypal account to receive payments.
Advertise your site as much as possible. Put it on social networking sites such as Facebook. Twitter updates regarding the site, such as thanking generous donors. Get your friends and family on board to spread the word.
Enlist volunteers. If you find people to support your cause, you can ask them to help you by moderating the web site, answering phones, and a host of other clerical duties. One person cannot run a successful organization. Many people are willing to volunteer for a movement they think is worthwhile, and those people can make calls, create flyers, and send out mailers.
Another way to raise money is to host fundraisers a few times a year. They can be as simple as a local car wash, or as elaborate as a catered casino night. These can very expensive, but don't be afraid to ask local businesses to donate goods and services for use during the fundraiser. This is another time that volunteers would be very beneficial.
Look for the unexpected donor. If you trying to raise money to keep the beach clean, hit up local businesses who may benefit from the clean-up. Always think about who is benefiting from your cause, even indirectly. Those are the people who may be interested in donating.
Send out informative mailers. Even if you don't receive donations, you are still getting your name out there and people will remember you over time. It may take a dozen mailings to reach a home before a donation comes your way. The constant reminder will keep your cause on their minds.