I too was blown away the first time I discovered orgasm by rubbing my frenulum. I always used to tease my frenulum for stimulation, but would always jerk off to finish. One day Solo Touch changed all that.
During lunch I started reading ST stories at work, and got really aroused. It had been a while since I had orgasmed, so I headed to the bathroom to relieve myself. I locked myself in a stall and dropped my pants, and I was leaking a lot of precum. So I started by rubbing that around my frenulum. OMG it felt good! Rather than jerk off, I continued slowly using my finger tip to circle my frenulum, and within a minute I was right on the edge of orgasm. I slowed my circles and just hung there, teetering in that incredible sweet spot.
And then I felt myself tumbling over the edge, and had the most incredible orgasm I'd had in a long time. Spurt after spurt erupted into the wad of tissue paper I was holding, and my knees nearly buckled as I moaned aloud. I now use this method regularly, using it to 'edge' is a sure fired way to heaven!