You see people in suits and ties riding the bikes because it's a convenient and effective way to get to work By Harriet Baskas Despite some financial and legal challenges, bike-sharing programs are rolling out in cities throughout North America. Locals and visitors in Minneapolis, New York, Washington and about 30 other North American cities can now buy daily, weekly or annual program memberships or pay hourly fees to check out a bike to ride around town. Cities such as Tampa; San Diego; Portland, Oregon and Vancouver, British Columbia, will soon be launching programs. Seattle is the latest city to announce that it is joining the bike-share bandwagon, with a start date in September for Pronto Emerald City Cycle Share, which will kick off with 50 docking stations around town for 500 blue and green bikes. As in other cities, grants, private sponsorships and user fees will make the bike-share program possible. But with a contribution of $2.5 million from Seattle-based Alaska