I was still using version 2.2.0 when I posted this question, I've since upgraded to 2.8.1 which has the advanced digitizer built in as standard.

What follows is a little bit of a tutorial for those folks who might be looking to tackle the same problem.

IMPORTANT UPDATE

I was still using version 2.2.0 when I posted this question, I've since upgraded to higher versions, which now have the "advanced digitiser" built into the core QGis application.

The answer below where it mentions anything to do with adding the plugin from the repository, is now deprecated and should not be followed.

If your still using an older QGis then the repository plugin is the only way to go.

The usage of the tool built in and/or plugin version however is the same, so I've left the original answer as is, in order to serve as a mini tutorial on it's use.

Original Answer Follows

I was still using version 2.2.0 when I posted this question, I've since upgraded to 2.8.1.

I was still using version 2.2.0 when I posted this question, I've since upgraded to 2.8.1 which has the advanced digitizer built in as standard.

• A : angle
• D : distance
• X : x coordinate
• Y : y coordinate
• Combine those with "shift" to toggle absolute/relative mode
• Combine those with "alt" or "ctrl" to toggle locked mode.
• C : construction mode
• P : parralel / perpendicular to a segment
• ESC : unlock all locked parameters

• A : angle
• D : distance
• X : x coordinate
• Y : y coordinate
• Combine those with "shift" to toggle absolute/relative mode
• Combine those with "alt" or "ctrl" to toggle locked mode.
• C : construction mode
• P : parallel / perpendicular to a segment
• ESC : unlock all locked parameters