You might think you're a great solo runner, and maybe you are. But when it comes to training for a specific event -- a 5K, a 10K, a marathon -- you really should consider joining a running group. It's a good source of support and motivation, and anything that keeps you going when all you want to do is sink into your couch is a good thing. Besides, it's National Running Day, so the more the merrier.

It's not hard to find the perfect running group, and Gadgetwise writer Danielle Belopotosky from The New York Times has made it even easier -- she did some digging and turned up these great discoveries.

• Road Runners Club of America -- Kristen mentioned this club earlier today. Just filter by state for classes, training schedules and a message board where you can locate running partners.
• Meetup -- search by country and zip code, and you'll find walking clubs, beginner runners groups, even triathlon groups. If you've already got a group of runners, this site can help you organize and plan meetings.
• Online groups -- Belopotsky found several sites that offer online running groups, virtual trainers and training partners. The most comprehensive of her finds are RunnersWorld, NikePlus, CoolRunning and DailyMile -- it's kind of like Twitter. You can also search Facebook for running groups.
• Charity programs -- if you're running in a charity event, like Team in Training or Team for Kids, you'll likely have access to a training program that takes you right up to race day.
• Local gyms -- ask the experts at your gym about running clubs they offer.