What if the company goes under?

I've noticed a lot of talk on here about APIs and this brought me to thinking "What happens if that company goes under?"

Many companies now-a-days aren't doing so well with the current economy and all, so what if you invested a large stake of your company into services that another company offered and that second company found itself in the red? How would you cope?

I would hope that these companies have thought of a plan, ahead of time, for a situation like this.

I was simply wondering what your plans are, or would be, should you find yourself, or your company, in the aforementioned situation?