NO LONG SUPPORTED OFFICIALLY AS OF AUG 8, 2016.
I recommend you just use TTW if you're unable to get this to work.

Description :.
This is a port mod of armors from Fallout: New Vegas into Fallout 3, generally porting is illegal even between games by the same developers or game series. So this does not contain any assets from Fallout: New Vegas, you will have to port the meshes and textures yourself which will be further described in the Installation section.

Currently the only thing added is all the vanilla headgear and armor from Fallout: New Vegas and its DLCs.

You do not need the DLCs for this file to work, you will just have four empty crates in the test room.

Please thoroughly read through all sections.

List of all the armors added. Big thanks to mindumindumindu. LINK TO PICTURE. Image is far too large to put in description, even with spoilers on.


Updates :. 
28 Sept. 2014 - All Fallout: New Vegas DLCs have been added


Requirements :. 
Fallout 3
Fallout: New Vegas
Dead Money, Honest Hearts, Old World Blues, Lonesome Road (Optional)
A little bit of patience and time. You will need to have knowledge of using the FOMM, .bsa's and how to generally port armors from New Vegas to Fallout 3. 


Installation :.

I highly recommend making a backup of your data.

REVISIT: I know the installation could be better wrote out. Sorry about that. At this point I can't remember how to describe installing it in further detail. I recommend you check out some YouTube videos and forums about porting from Fallout 3 to Vegas or vice versa (it will work the same both ways.) Also be sure to check out the image by mindumindumindu in the image share or the link above, you can see exactly what armors are used.

I. Open up your Fallout: New Vegas data directory and find the Fallout - Meshes.bsa and Fallout - Textures.bsa.

II. Once you find those two .bsa files open it with Fallout Mod Manager.

III. a) Extra the armor files from both the textures and meshes .bsa to your Fallout 3 data.  I am not going to list all the files to bring over because there are far too many to list. You can either just extra all the armor meshes + texture files, or you can extract get files manually. Extracting files manually is the best way because it keeps Fallout 3 less cluttered file wise and also won't overwrite Fallout 3's armors. If you extract all the armor files expect file overwrites. You will just have to reinstall your armor mods that are affected (ex. if you have a texture overhaul like BoS DX or a mesh change on vanilla armors).

III. b) Forgot to mention you will also need to port the icons, this is their directory - do this for DLCs also. 
Fallout - Texture2/textures/interface/icons/pipboyimages/apparel

IV. Activate my .esp so the armors are actually created into the game.

Easy.

A little tip for extracting manually. You may notice when trying to highlight the files it won't let you drag up and quickly highlight all the files, instead you have to click each one. A way to bypass this is scroll all the way to the bottom and bring your cursor just below the last file, click and make sure you haven't selected a file, then you can move the cursor up and quickly select the files.

Installation for DLCs :.
Follow the same steps above, extract the armor meshes and textures from the DLCs .bsa.


Location :. 
The location of all items can be found in the test cell by typing - coc TestQAItems - in your console.


Known Issues :. 
Some of the headgear appears on sideways above the left ear - rather than on your noggin. This is common in porting and will be fixed in further updates.

Not every single armor or headgear is incorporated, I left out one or two on purpose. Others I forgot and will be added in the next update. If you can't find the armor you're looking for it might have been renamed. If not let me know and I will add it.

If you come across something such as; gloves on an armor set that shouldn't have gloves, hats on sideways, etc. let me know the armor name so I can fix it.


Future :. 
NO FURTHER UPDATES
Fixes for the headgear. (In progress)
Incorporating all armors into Fallout 3's leveled item list so you see NPCs wearing them. (In progress)
Possibly adding all chems and weapons + mods. Maybe even casino games.
Adding all Fallout: New Vegas DLC armors. (In progress) Added in version 2.0


Permissions :. 
You are NOT allowed to modify this mod and release it on other sites or the Nexus, all changes you may make must stay with you. If you want to make a change and release it make your own mod because I don't want to be get in trouble for something you may have done wrong.

If you are in need of help comment or send me a message.