Our planet breathes a small sigh of relief every April 22 when we observe Earth Day. In the 28 years since the birth of the event, it has helped to show us that when it comes to a healthier environment, little gestures can make a big impact. These Web sites provide some simple tips to further the cause:

hulagirls.com Play online games-starring princess of the sea, earth, and sky-that raise environmental awareness.

dividetheride.com Create a carpool schedule with families you know, complete with e-mail reminders.

imbee.com/group/natgeokids Encourage your kids to join the national Geographic Kids online network to learn more about important environmental issues and what other children are doing about them.

paperbackswap.com Trade a book you've finished for one on your reading list;
it just takes a quick trip to the mailbox.