OK, I’ve got 3 objects, each with their own armature. (I originally had 1 object & armature which I duplicated for the sake of convenience) The problem is that everytime I pose 1 object & lock it, the rest take the same shape. Basically the 3 armatures are linked & moving together when I want them to move separately. Can anyone tell me how to fix this?
Select each Armature (and Meshes too probably) in object mode and hit U >> 3.
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fix as in…make them all separate? You have to make the armature what we obscurely call ‘single user’. right now there are three users of the same set of poses an Ipos.
In the Editing buttons set, the Links and Materials panel, next to the armature name you see a number, like 3. click it and Blender says hey, you want me to copy this sucker a few times, or what? So you like say Hey, yeah, I do and whatcha gonna do about it, punk. And you click and it does it and everthing is okay cause everbody got their own copy now, and life is good. YaknowhattaImean?
Neither of those worked, though I did fix the problem by renaming all of the bones. Thanks for trying anyway 
Well for future referene, you didn’t need to rename the bones.
It sounds like you duplicated the armature after keyframing the bones in POSE mode, therefore creating an Action. When you duplicated the armature, the new armature is automatically linked to that Action. All you have to do is “disconnect” the armature from that Action, by clicking the “X” button in the Action editor.
The default for duplicate SH-D is to create a new armature (check the User Preferences Panel / Edit Methods / Duplicate with Object, the Armature button is on by default), so that’s why the “single user” advice given didn’t work.
You can check the OB:(ject) and AR:(mature) names in the buttons window / Editing (F9) / Links and Materials Panel
Here’s a good explanation / tutorial on :
Blender’s Datablocks
Mike