Textured plane in 3D Viewport?

I want to put a guide-image on a plane in order to be able to see it in all directions while modelling -instead of having a standard background image that doesn’t work in other angles than directly facing the viewport. I have selected textured shading mode in viewport, assigned an image to a plane but it only appears if I render it -not in viewport. So is this possible?

In the Properties panel (shortcut N) under Display, set the shading to GLSL
Also look at the Images as Planes addon to easily add textured planes http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Add_Mesh/Planes_from_Images or add an empty and it its properties you can set it to display as an image

Thanks! GLSL + enable “Images to Planes” addon works well. I’ll keep in mind Sanctuary’s suggestion too.

Without using addons - add an Empty, in Properties dropdown for that set Image.

Update:
“Images to Planes” addon, incorrectly displays images in low resolution, blurry and aliased. Too bad for a precision blueprint.

Empties though, leave the image in its native resolution, thanks Richard Marklew and eppo for the suggestion!

BUG:
“Origin offset distance” in Empty Object Data displays only the first two decimals of the adjustment! Inadequate for precision image placement.

BUG #2:
Y component of “Origin offset distance” is NOT saved! After loading it resets to zero!

BUG #3:

It also resets arbitrary to zero in many cases, e.g when you change the resolution of an icosphere!

If you think those are bugs, you really should post them on the bug tracker :
http://projects.blender.org/tracker/?group_id=9
This way the developers will notice and may be able to fix them.

Image on Empty: See T-panel for precise Translation numbers. Hold Shift while adjusting position for a fine tuning.
y position (0.0023) saved, restored 3 out of 3 times. Supposedly saw one sudden jump to 0 once…
There’s possibility to lock transform on N-panel after set position. Could help.

This is quite strange. I have no resolution loss here using the addon and I can’t see how there could be one…