Appeal to busy people who don't have time for two hobbies. Radio-controlled model ships add a new dimension to fishing. Remember those life preservers. Make money with skills developed at golf. An elaborate scatological vocabulary and variable math skills are in demand in Hollywood.
Gardening is in again.
Make your backyard an earthworm ranch. Remember, you'll need horses with extra-short legs for the annual roundup. Make a gardening hobby pay off big even if you're condo-bound. A surprising variety of plant vines can be dangled off a balcony railing. Be sure to pick your tomatoes before they ripen and fall off the vine.