Quicksand by Andrew Paglinawan is today’s free font. It has 7 weights (light, light oblique, book, book oblique, bold, bold oblique and dash) and is free for commercial use.
I really like the light version, but all of the weights have their charm. I can see myself using the dashed one a bit as well. Quicksand is a nice, sans serif font that is very legible.
You can download it here.