Are there any spoons that come with a catch or ridge near the end so they don't slide into my big cereal bowl?

You just gave away a million-dollar idea.  That's a good one!  Go for it.

In prison they had something called a spork. It was a cross between a spoon and a fork. It had ridges at the end of an oval shaped plastic spoon. Using them to avoid sliding into your cereal bowl was not what they were famous for. Stabbing other inmates was there main usage.

Use an iced tea spoon or eat from a large mug.  

Yes, the Chinese figured this one out.

Why don't you just lay it on your napkin like everybody else does?

Extend the handle with 5-10 inches of rubber tubing pulled down over the handle. that makes the spoon too long to fit in your bowl. You can also find long-handled spoons in some stores. they are usually intended for mixing salad and survive the dishwasher better than the rubber tubing do.