http://files.sims2graveyard.com/shaklin/Look for the file called "model_animation_changer.rar". When you put it in your game, it will show up under Decorations => Misc. as a pink flamingo. Once you have it on your lot, you click on the flamingo for the options to appear to change the selected sim's facial animation, walk style, or even make them do a little pose (mainly the teen "check self out" animations).
As for the pose boxes... well, if you only have the base game and no EPs, there's a chance they're probably moot in your game. :? The only one I know that works well without any EPs is this one:
Ceedj's TS2 Studios Machinma Tool Of course, I'm sure some of the others, like Aikea Guinea's picture mods, will work also... you just won't be able to use certain options without the required EPs. Anyone else that knows for sure can feel free to correct me on this... :dontknow:
But, you can check Jaydee's site for tutorials on doing
Overlays and enabling the '
allmenus on' cheat*. :angel:
*
Make sure that if you do try this, back up everything in case a mistake is made. Not trying to scare you away from it, but better safe than sorry! 
