The website itself is an application, so should be designed with that in mind. But right now the website looks too much like an application - I would like it to look less clunky. I think pinterest.com captures the balance right.
Home page: the current home page isn't engaging or functional enough. I'd like to have a home page which lists the current user's Roobricks and any recent activity that has gone on within them (new picks, comments). You don't have to use any of the graphical elements on the current home page except the logo (if possible, not required). I do like the look of the example Roobrick List on the home page (the one that has the pictures in it).
Roobrick List: this page lists the current user's Roobricks and allows him to drill down into more details for any of them. It also shows his current "house" and some other details of the Roobrick (e.g. how many bricks it has earned). This should look more like the example Roobrick List on the current home page, or something better.
Picks/Links: these pages list picks and links on a Roobrick and let the user do other things with them (add pick, invite). It's possible that these two pages might be combined into one, if that design worked on a mobile device (see below).