A few of my favorite finance blogs...
http://gregmankiw.blogspot.com/ Excellent for big picture economics
http://freakonomics.blogs.nytimes.com/ Interesting, often a little more obscure economics related stories
http://financialrounds.blogspot.com/ Finance postings by the "Unknown Professor" - good stuff and often quite humorous.
http://www.portfolio.com/views/blogs/market-movers/ Excellent analysis of financial markets and deals.
Another finance academics blog. More good stuff.
Did I miss any good ones? Please add a comment if you have any suggestions.
A commenter pointed out that I missed this 0ne - this is a great blog that looks at academic research and tries figure out whether the research has investment potential. Well worth a read. Thanks Wesley!