If the recipe says simmer beans for 3 hours, can I just turn up the heat and cook faster? I just got home from work, and tonight is my night to cook. Unfortunately, I just realized this recipe for Mexican beans says I should simmer the beans for 3 hours. I'm too hungry for that, but I really want to eat these. 

Would be okay to skip the simmering? Or is there something else I can do to produce the desired effected?
You probably want to just use already-cooked beans, from a can. (Hope there's a store nearby.) Then you just have to cook as long as it takes to let the flavors mingle; half an hour is plenty.

If you happen to have a pressure cooker, you can cook dried beans much faster, something like 20-30 minutes. See for example this recipe - you can add back in whatever seasonings you like from your recipe.

But otherwise, there's no way to speed up cooking dried beans - boiling water doesn't get any hotter than 100C, and it just takes time for them to slowly soak up water and cook through.