Bone Animation - Hide parts of the object?

Is it possible to hide and show different parts of my object during an animation (using bones)?

If it is, how would I go about doing such a thing? E.g. the MD2 of Yoshi in tutorial 14 he has a gameboy that appears in his hands for only a few frames. How would I go about doing something like that in blender?

Not with the SIO2 method... its based on VBO...

You'd better use the MD2 loader if you want to do something like that where every frame are exported as a full mesh...