LegoBlock lets you create a small block to display information in it like time, performance, haste or anything you can think of! Blocks can be snapped together in any position or order you can do simple things like snap them together into a long line to be positioned at the top of your UI, or you can snap them together in an "L" position and so on.
Theres two methods of snapping blocks together, one is simply to drag it to another block and it'll snap to the closet block for example if you drag block "A" to the bottom of block "B" it'll snap to the bottom, if you snap it to the left side of "B" it'll snap to that side and so on. If you have muultiple blocks and you need to specifically choose which one to snap to then drag block "A" into block "B" and you can choose which side to snap to without it trying to snap to anything else.
Blocks that are snapped togther become a group, if you have A, B and C you can drag any of those 3 and they'll all move together when you want to unsnap a block from a group hold down CTRL and drag it out.
LegoBlock is meant to display information, not as a methods of launching or viewing configuration.
For API see http://www.wowwiki.com/LegoBlock