This winter I'm using an EMS (Electronic Muscle Stimulation) device for the first time ever. I typically do quads for 30 minutes each, 2-3 times a week. Sometimes I do my hamstrings for a little variety, but that's about it. Once I even used the gadget to massage by back, but I don't think it was quite as effective as real massage.
I've enjoyed the experience so far, mainly as a form of active recovery after days workout. EMS also possibly adds some extra strength and endurance. It's too early to say any more than that, but some athletes have reported good results. EMS does not substitute conventional training, but I'm hoping it might help my legs survive the long downhills of this year's alpine ultra trail races.
If you'd be interested in more information, here's The Truth About EMS. Although the article is written for bodybuilders, in my experience it applies to runners too.
For additional inspiration, check out the incredible story of Marc Herremans, the Belgian triathlete who paralyzed chest down after a bicycle accident and then went on to realize his dream of winning the Hawaii Ironman Triathlon World Championship.