How do I render text onto a prefab?

Let's say I have a prefab (e.g. a crate), and I would like to render a configurable piece of text onto its surface. Is there a way to do this through scripting, rather than having to have a texture for each piece of text I want to display on various crates?

Are you talking about a decal sort of thing? Are you using Unity or Unity Pro?

Pro: You could set up a second camera with culling set to only a single layer. On that layer would be only a GUIText object (camera's clearing set to depth only as well) and render that to texture and have that texture referenced on the crate.

For Non-Pro: I would probably suggest the ladder of your initial post.

You could add a 3D Text game object to your prefab (Game Object->Create Other->3D Text).