This should help
http://goofans.com/developers/world-of-goo-level-editor/faq#play

Edit: Oh and....
Just took a look at the goomod...
1) Seems GooTool doesn't like addin names that are only 1 letter.

2) When you get it working you'll find that all your Goo's will disappear.
This is because the line at the top of the level (labelled "ground"?) is facing the wrong way, and it will throw all the Goos up off the top of the level.
You need to rotate the line so the "normal" is pointing down.

thanks working fine now one question how can i add balls like the ones from metal sandbox to my level?

install metal sandbox.
add a common Goo Ball (or any other type) to your level in WooGLE.
change it's type property to the name of the metal sandbox ball you want to use.
(you should be able to find it in the dropdown list, when you type something in the type field. if not, open the metal sandbox level and look up the ball type names.)

you have to be careful with that.
If you use metal sandbox balls in your level and you don´t put everything, what belongs to the ball, in your goomod, everyone who didn´t installed the metal sandbox couldn´t play your level.

hm. You could have a point there. I just assumed WooGLE would be smart enough to put the "foreign" custom balls into the new goomod.

It IS!!!

or at least... it asks you if you want to include them....
and anything they depend on.. like 'contained' balls, custom particle effects... etc

Oh. goomatz weakened my belief for a second, but now I know it was BLASPHEMY! I am deeply sorry to have misunderated the almighty power of WooGLE.
*goes witchhunting goomatz*

sorry
i just thought there could be a problem because of the picture problem in Garbage Dump level

By the way programme/Computer are always as smart as their programmer/user

Oh yea of little faith...

Plus.. the "Garbage Dump" image problem is sorted in the latest version.... I think!

Edit:

so you have done a realy good job with WooGLE

Hi,
I haven't been able to fix the pics yet sorry!
It's just that I'm on vacation and I don't have Woogle with me...
@DaB
Could you make a portable version of WooGLE like the Portable World of Goo application? I have Portable World of Goo on my flash drive with me and I can use it.

EDIT: You could even make it part of PortableApps.com! I like them...

Meh. PortableApps isn't good for shareware programs. If there's the need, I can try making WooGLE Portable. Of course, I don't use WooGLE... But the source code for WoG Portable is out there if anyone would like to wrangle with it. Of course, support within the app would be better than anything outside that has to move stuff around.

GMMAN YOU ARE AWESOME!
I mean, with the WOG Portable thingy.

So far as I can think, there's only 2 things that would need changing in WooGLE to make it "portable"...
1) Load and Store settings from a file in the app folder (rather than Windows Registry)
2) Make it store the path to the WoG directory as "relative" to the app folder rather than absolute (with drive letters)

I don't think that would make it portable by portableapps.com standards, but it ought to make it work on 99% of Windows machines (XP and up)

Source code's available ..... off you go!

Guess what.
("What?" a gooball says.)
I come home from vacation and... (dramatic trumpet music) my computer isn't working!
(sigh)...I won't be able to upload my addin for...a few days... at least...
Or modify WooGlE for that matter.
So could somebody do that for me please?

OK, working.
I put up a link to the images so you can download them.
Later I will post version 1.0..