Second zerohedge.com and also tickerforum.org, and learn the lingo / slang / inside jokes if you want to participate, expect a fair amount of dark humour, it's how people cope.

I think you need to narrow your search parameters a little bit here. Just as there are thousands of sites about technology, so too are there thousands on which you can discuss finance. HN is unique in its potent mix of entrepreneurial minds and technical folks; what kind of analogue would you seek for finance? A particular niche? Or just 'real cool people'?

Zero Hedge is nice, check out also other blogs online that you might like, and at least follow along in their community :)

http://stocktwits.com is pretty awesome

along with their great blogs/contributors

zerohedge.com (sucky Wordpress style comments after article however) ; minyanville.com ; and many more, depending on the focus - what exactly are you looking for? Your scope is pretty broad.

I've been looking for blogs dealing with commercial real estate. Any ideas?