Our happy face spider was a little over 1/2" long and about 3/8" wide. A half inch is a very large size for our local jumpers which usually range about 1/4"-3/8" especially the little black and white ones, that typically live on our light colored walls, and seem to feel comfortable with our comings and goings in their presence.
Our Happy Faced Spider might just have been a traveling marauder, as it seems to have exited our yard. It was around for about 48 hours, but hasn't been seen since. But I think it left a trail of empty exoskeletons in its wake. I must say, to exist at her scale, it must be a frightening existence when she suddenly shows up at a party. I dare say, she must be a formidable opponent, a real party crasher.
a.k.a. Phidippus audax (daring jumping spider or bold jumping spider)
**Update! The Happy Faced Spider has returned! I am not sure whether it is the same one, but in August 2012, one day I stepped out and there was a Happy Faced spider on my wall again! And shy it was, just like before. I was in the process of departing so I did not get to watch this spider, but it was definitely a Happy Faced Spider. So that makes two visits now. Funny, I always look at every black spot on the wall now whenever I am coming and going.
note: I posted this because I found a blogger that has also seen this same spider species, as have some of her commenters!