Theme CSS Editing
A couple of days ago Wordpress.com introduced a new option for their bloggers, the ability to customise the CSS file of the Sandbox Theme, for a small cost of around $15 per year. Not to be out done, i’ve made my own user CSS editor. It stores a local copy of the CSS file of any Theme on the site, for you to edit in the admin area, and it won’t cost you a penny to use. 
For those not familiar with CSS and what i can do, it is a file that defines the style of a page - anything from font size to background color. Whilst it’s not quite as flexible as being able to make your own Themes from scratch, it does allow you near complete control over where to place elements on the page, and to an extent how they look. More info can be found here
Finally, i have uploaded the latest Sandbox Theme, as it is the easiest Theme available to go wild with using customised CSS output. You can use this feature by logging in to your Admin area, selecting the Presentation menu, and then clicking on CSS Editing.