I've been trying this:
http://www.blendernation.com/2007/02/13/compositor-unsharp-mask-and-ambient-occlusion/
in the way I do it get a blurred render but not DOF, has somebody tested it?

no i find depth of field boring.

for some free stuff i made
and for almost daily fotos

For depth of field you need to use 2.43 and use this:

http://wiki.blender.org/index.php/Manual/Compositing_Nodes_Filters#Defocus

Pay close attention to the camera settings part. Place the yellow cross where you want the focus to be.

I have some sample results here but of course people have put cooler stuff on Blenderartists and I think oodmb's egg picture uses the Defocus node.

http://l333la.googlepages.com/blenderimages

I generally do DoF in post work in the GIMP.....

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Toolset: Blender, GIMP, Indigo Render, LuxRender, TopMod, Knotplot, Ivy Gen, Plant Studio.

GOG_CA1,

That is pretty much out of the question for an animation over a minute or two. For stills your're right its probably easier.

The original post didn't mention animation just how to set up DoF......

That said I have applied DoF to animations in GIMP using script fu to load the sequential bitmaps, that assumes that you're not dynamically refocussing the 'camera'.

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Toolset: Blender, GIMP, Indigo Render, LuxRender, TopMod, Knotplot, Ivy Gen, Plant Studio.

Thanks l3la and Gog_CA1 for the help, I have a program called Defocus Dei for doing this in post work, but as the DoF in Blender is almost a postwork as I understand it I wanted to do it inside Blender and sorry I didn't say it's for stills pictures.
Tank you Again for the constructive answers :-)

Try using YafRay. It has native DoF support and has built-in integration with Blender 2.4. (You still need to download it, though www.yafray.org).

It is better to do one thing well, than to do many things and excel at nothing.