I like making poses in blender using the shapekeys thing but I don’t know if unity can use those. Do I have to like, make a script or something so blender can access the different poses I made with the shapekeys?
You will need to get one of the morphing/blendshape solutions in the Asset Store to get that working or write your own system, there is an example script on the wiki if you feel like coding your own solution.
Shape key support directly from Unity is planned, but not yet released as you can see here: http://feedback.unity3d.com/unity/all-categories/1/top/active/graphics-builtin-morph-target- .
Meanwhile there are some tools in the asset store which support it. As far as I know, MegaFiers has some functionality in that direction.
Edit: The guy who posted a few seconds before me implemented MegaFiers but forgot to advertise it 
Two free, but perhaps limited solutions (depends what you want to do with shape keys) are:
- Tagarela - http://rodrigopegorari.net/blog/?p=241
- Metamorph - see my post a little way down - Blender, Metamorph, Unity and shape Keys revisted - and this video I created : http://www.youtube.com/watch?v=FIFHGRDqTUY
The latter method will not work for Blender 2.63 and above because of changes in the Blender Shape Key functionality when BMesh was introduced.
cheers,
gryff
Awesome. Thanks for that post gryff; I just got Tagarela working. (And thanks to Rodrigo Pegorari for making it!)
I was hoping to use the animated collider mesh as well, but I have since learnt that doing so is too slow to be realistic.