Do a little good this holiday season and help out your favorite cause with two free services that make donations whenever you shop online.

Established in 1997, iGive works with 900 stores that will donate a percentage of your purchase to your chosen cause. Simply sign-up on the iGive website, decide what cause you’d like to support and add the iGive Button to your browser. Whenever you shop at a participating store, a donation from the merchant is made automatically. When you join $5 will be donated to your cause, with another $5 donated with your first purchase. After that, the percentage donated with each purchase varies with each store. According to the iGive website, the average shopper raises over $50 a year with the iGive Button. The small donations can add up. Last year alone, iGive users raised more than $384,000, according to Mashable.com. Participating merchants include Amazon.com, Barnes & Noble, Home Depot and Macy’s, to name but a few.

Causes and charities that would like to join iGive and start raising funds can find more information here.

Another service, GoodShop, also helps you make donations when you shop and when you search. Like the iGive button, the GoodToolbar is added to your browser, and a percentage of your purchase is donated whenever you shop at participating stores such as Best Buy, the Gap or the Apple store.

If all that shopping makes you hungry, you can earn more donations for your favorite charity through GoodDining when you dine at participating restaurants. Both GoodSearch and GoodDining are products of Good Search, a Yahoo! Powered search engine that says it donates 50 percent of its sponsored search revenue to causes and schools designated by its users.

Both iGive and GoodSearch services are free to both members and causes. However, while anyone with a cause can sign-up for iGive, only nonprofit organizations with 501(c)(3) nonprofit status or schools can register with GoodShop.

Charites can find out more information about GoodShop and GoodDining here.