Make Angled Guides in Illustrator CS5
In Adobe Illustartor CS5, you can select/click, hold the mouse, and drag the Vertical ruler to make a vertical Guide (Cyan Color by default). The same can be done with the Horizontal ruler to make a horizontal guide.
The Preferences panel shows this for Smart Guides. I don't know if it's related or not.
In the following image, I have both horizontal and vertical guides. I also have a line segment placed at a angle. How would I go about creating a guide at that angle just like the other two guides. That is, a guide which is not vertical or horizintal but at a angle like the line segment.
Draw a path..... any path..... Select it and choose View > Guides > Make Guides.
With the Make Guides command you can turn any path, or series of paths, into guides, whatever those paths may be.
The below involves a third party solution so I'm adding it just in case that's an option.
Within VectorScribe there's a panel called the Protractor Panel:
What this panel does is allow you to alter Illustrator's default X/Y graph and constrain angle to anything. For example, you can click the "30" button to change the X coordinates to follow a 30Â° angle. THe red line on the panel indicates the currently set angle. If you want a custom angle, just click the box with the red line in it and enter the angle you want.
Once you set an angle, the Illustrator grid will be rotated to match the set angle.....
With this set, you can then actually draw at that angle (I turned off the grid because Illustrator's screen refresh is just poor, you have to zoom in and out to get the grid to refresh which I didn't think was important for the image below.)......
No keys or shortcuts are being used I'm just dragging with the rectangle tool.
Once an angle is set objects traditionally horizontal are created at that angle, shapes and type being the most noticeable. This essentially allows you to work at an angle other than 0Â°.
The only way to do that is like @Scott is saying in his answer, but...
I just wanted to clarify things about Smart guides cause I see you posted a screenshot about that in your question, I hope this will help you understand them better:
Smart Guides are not directly related to normal Guides in Illustrator(the ones you manually drag from the Ruler,
Smart Guides are those green guides that appear when you select and move an object in Illustrator, not your typical bright blue Guides that you drag from the Rulers, but these Smart Guides appear by themselves when you move an object, they have a bright green color, have a look at the screenshot, the birght green lines, that say "intersect" are the Smart Guides: