i tried panning once, you spend hours sifting sand in a freezing creek to get a few flecks of gold. you might get luckey and find a nugget. its a lot like gambling away time to get money.
I had gotten interested in panning after regularly seeing some folks panning on a stream I like to hike along and wondered if they were getting any gold out of it. So one day I decided to walk up and talk with one of the old timers there. So glad I did, too, he seemed to love the attention. Sat with him for hours as he panned, taught me the basics, and recounted some awesome stories over some beers. One of the coolest guys I've ever met.
But yeah, I had figured they were only doing it as a hobby and I was right -- around here there just isn't enough to find. If someone was thinking of doing it for profit then I'd suggest they try something else, because unless you're extremely lucky, in a very high producing area, or going all-in with equipment (dredging or metal-detecting), then you're probably making less than minimum wage despite putting in a lot more effort, and **** that. For me it's about spending time outdoors, learning a bit about geology, collecting native minerals, and if I do get gold it is a nice bonus.

@deathfun:
Here ya go. It is non-magnetic, dark grey with metallic luster, and has a specific gravity of at least 4 g/cc. So I'm pretty sure it's galena but maybe I'll crush a piece for a streak test to be sure.