Mint is a great looking website/application, these guys have come a long way since they first launched.
Mastering Grids in UI Design: The Backbone of Visual Harmony
A modern guide to UI design grids, learn how to build flexible 12-column and 4-column systems, master margins, gutters, and modules, and apply today’s responsive layout best practices.
Hmm, I might have to have a look at this. I’m hoping to get me a new place soon and this kind of thing might be useful.