Hi everybody
I discovered Blender many years ago and I even participated to the money collection to buy it out from that venture capital company that owned it previously (a pity that sponsor list doesn’t seem to be online anymore). Since then, I never used it again, however now I want to use it and its sophisticated interface to plan some woodwork.
I know that the Blender Unit does not have a specific meaning in terms of meters, but it also doesn’t matter: only relations matter for my purpose. However, I would like to change the length of an edge in a way that I can set it to a length of say 0,5 blender units. I have been unable to do that up to now - when I move a vertex it just shows how far I move it, not the length of the edge. Is there a way to display the length of an edge, and to adjust it while I change the length?
It would make my modeling far easier if there were such a feature hidden somewhere 
Regards,
Aurelio
You haven’t used Blender for all that time?
Wo! Do you still find your way around?
Anyways, in the Edit context (F9), Mesh Tools 1 panel, there is an Edge Length button to press: this will make it so the length of the selected edges is displayed on the screen and updates while transforming.
Be very attentive that the scale factor of your Object (in Object mode) is of 1 for every axis otherwise the length displayed would be inaccurate.
Welcome back. 
Jean
In the editing section (F9) there is a panel called “Mesh Tools 1”… switch on “Edge Length” to get realtime feedback on the length of an edge as you edit it etc.
Damn, too slow
I KNEW IT!
Indeed, I knew that Blender has almost everything one needs for almost every purpose, one just needs to know where Thank you, Jean and ardee. That is what I was looking for…
And thank you for welcoming me back, Jean. When starting up Blender a few days ago, I noticed that I had lost my cognition of the third dimension on this terribly restricting two-dimensional screen, but it is like languages: when you stop talking a language and start over two years later, you find that after a few weeks you get back all the talent you had had. That feels good!
Regards
Aurelio
Welcome back!
I don’t know what you remember or not, but when moving verts and edges, pressing X once constrains to object axis, pressing again constrains to local axis (like the edges’, and a third time goes back to free form.
there is now proporational editing that proportionally moves surrounding non-selected verts.
there is now a decent user manual. http://wiki.blender.org/index.php/Manual
There is also a dimensioning script that I just revisted 1.4 in a building plan I am doing.