One of my readers commented that they were looking for this really cool flash presentation that I blogged about a while back -- it helps you visualize higher-dimensions all the way to 10-dimensions. Check it out! After this your brain will need a rest, and possibly a hard reboot -- but worth it.
By the way, a reader named Runde has discovered that this visualization is not exactly in accord with the view of string theorists or mainstream physics. You can read the criticisms here. Oh Well, that's too bad -- but I think it's really cool anyway because it is an exploration of higher dimensions from the perspective of true metaphysics (metaphysics in the philosophical sense, as opposed to new-age metaphysics).