|the Santa Ana River Trail|
The 26 (and growing) mile trail is a great way to see two professional sports stadiums, three California communities, and more flowers than you can shake a stick at. And if you're feeling adventurous, rent a fun set of wheels for a change. Don't feel bound to your usual road or mountain bike. Try a cruiser bike, or a tandem, or a 3GStepper, or ....
All of these options are available at rental shops in Newport Beach. And since the trail is smooth concrete/asphalt and fairly level, now would be a good time to experiment with your blood powered transportation.
For more information about the trail, check out the Santa Ana River Trail guide on Everytrail.com. You'll love the trail and download the guide. Preferably not in that order though.