I'm glad you found it in the garage before you drove it. The clean up part sucks though! Hopefully this will make you feel better:
I did the same thing back when I used to change oil in my DD's. I changed the oil in my 97' Civic one evening and same as you I thought it took a little too many turns on the oil filter to get it tight. Here's the REALLY stupid part, when the oil filter leaked a few drips while running the engine I just gave it another 1/2 turn. Hey, it stopped the leak!
I got up early the next morning and drove 30 miles to the airport on the interstate at 70-75 mph, took a flight to Indianapolis and back, and then drove home. The oil light came on within a mile of the house, but it was late and I was tired so I figured I would check the oil level in the morning. I went outside the next morning and there was a trail of oil out of my garage and down the road. Alarm bells went off when the oil trail stopped about 1 mile from my house!
I did another oil change expecting to get a few drops of oil, a lot of oil shavings and maybe a few small engine parts out of the drain plug. Luckily only oil came out, but I couldn't have filled a coffee mug with it. And not one of those gas station sized coffees either. I'm talking one of those regular size mugs you have up in your kitchen cabinet that your kid got you for Father's Day.
After the oil change I drove the car for a couple days with no problems and figured what the hell, I'll just wait till it blows up and then replace the engine. I ended up driving that car for another 75,000 trouble free miles.