I know so little about music technology it's painful but I know that some of you guys will have an idea as to what it is I need.

I play guitar and sing in a three piece and would occasionally like to be able to be able to add pre-recorded sounds during live performances. These sounds could range from extra vocals, guitar or ambient effects.

I'm thinking that I could maybe control this via a foot switch of some kind but I don't know what kind of equipment I should be looking for. Also, could I play this through my guitar amp or would I be better advised with a separate amp/speaker?

Anyone have any ideas?

Thanks.