1. Jordan Ellenberg's review of Andrew Hodges' book One To Nine. Read the review, if only because it uses the word "mathiness". Ellenberg's review seems to imply that the book has similar content to most popular math books; sometimes I wonder how the publishing industry manages to keep churning out these books, but then I remember that the same thing is true in most other subjects and I'm just more conscious of it in mathematics.
2. Open Problem Garden, which is a user-editable (?) repository of open problems in mathematics. Thanks to Charles Siegel, my fellow Penn mathblogger, for pointing this out. The majority of the problems given there are in graph theory; that seems to be because Matt Devos, one of the most prolific contributors, is a graph theorist.
But I have to say that "garden" feels like the wrong word here; gardens are calm and peaceful and full of well-organized plants, which doesn't seem like a good way to describe problems that haven't been solved yet. "Forest" seems like a better metaphor to me -- certainly when I'm working on a problem that's not solved, it feels like hacking my way through a forest, not walking around a garden. Also, the use of "forest" enables bad graph theory jokes -- the problem of "negative assocation in uniform forests", due to Robin Pemantle, in particular sounds like it could be about sketchy people you meet in the woods.
(I gave a talk back in February where I mentioned this problem. I'm glad I didn't think of that joke then, because it's really bad and I would have just embarrassed myself.)