Object snapping and rotation issues

I know you can use the grid to align objects, but is there a way to snap objects together in SL?

Also, if I'm building a wall and the wall turns 45 degrees, how can I correctly align the corners?

Here's how I do it: Move the wall section to be rotated so that it's pivot lies on the X/Y position of the final edge. Rotate the wall section. Set the ruler mode to Local. Move the wall section 1/2 its width and 1/2 it's thickness. Voila, the corners are aligned.

Here's what I do:

1. Select one of the walls (call it Wall1 for now) and press shift-G (with chat closed, of course) to activate the reference grid. Wall1 is now the reference point for the grid. Make sure you have Use Grid turned on, by the way.

2. Select the next wall (Wall2) and snap its center point to the edge of Wall1.

3. Set the ruler to Local mode, slide Wall2 over, and snap it to the half-thickness mark. The edge of Wall2 will now be perfectly snapped to the edge of Wall1.

4. What we just did will have aligned things along just one axis. Repeat the process to snap in any other dimensions as needed.

5. If you want to check the acccuracy visually, go into wireframe mode (ctrl-shift-R) and zoom in on the edges. It's often a lot easier to tell what's going on by looking at wires than by looking at shaded surfaces.

Happy aligning.