UPDATE: Another Blender user named Slight has added some features and fixed some bugs in this importer. His modified files can be found here, and I recommend using this version, as it works with the current version of Blender (2.71 at the time of writing) as well as being improved over the original.
Recently I've been trying to learn how to use Blender. As someone who has worked as an artist in the game industry for quite some time now, I've gotten pretty used to using Maya, but there are so many things I hate about it (not least the $5000 price) that have made me want to learn how to use Blender for serious work. So far I've not exactly become a Blender expert, but as part of my Blender training I decided to do write an add-on.
The addon in question is a Quake (1 of course!) .bsp importer. You can give it any Quake 1 level and it will load all the meshes contained in the .bsp, which also includes loading the textures (stored inside the .bsp in Quake 1 and Half-life) as materials and applying them to the mesh.
Download: blender-quake_bsp_importer-v0.0.4.zip
BlenderArtists thread here.
Quake 1 BSP Importer for Blender
Usage
1. Extract to blender scripts/addons/
2. In user settings go to addons and enable 'Import-Export: Import Quake BSP format'
3. from the File menu, select import>Quake BSP (.bsp)
4. Choose a valid Quake 1 .bsp file
5. Assuming everything worked, your scene should contain all the models in the bsp,
though you may need to move/rotate the camera to see them.
There are several options available when importing:
+ Scale - scale down the level on import (default 0.05) Quake units are 64units ~ 2m (assuming Quake guy is short and stocky)
+ Create materials - enable/disable creation of materials (default on)
+ Worldspawn only - when enabled, only the first model (the worldspawn entity, or main level geometry) is loaded. (default off)
History
0.0.4
+ fixed crash bug caused by texture names not being 0 padded in many older bsps
+ prints bsp version on import (only to terminal, most users won't even see this)
0.0.3
+ added scale option (scale geometry on import)
+ added create materials option (use textures from the bsp to create and assign materials)
+ added worldspawn only option (import just the main map geometry, not doors, triggers etc.)
0.0.2
+ now imports textures from the bsp as materials
+ uvs and materials are applied to faces
0.0.1
+ import bsp imports all models in a bsp file as objects in a blender scene