newbie here, protoshield and why do I need one?

I see what it is sorta, seems like a quick way to interface wirings up to a arduino board? Am I right? Why do I need one? I just got a decimilla, and no other "Goodies" anything else that is recomended to buy too?
Thanks,
Shane

About the prototyping shield, does it offer much of an advantage over the 1cent shield? (from todbot.com):
http://todbot.com/blog/2007/11/14/the-1ยข-arduino-under-shield/

you don't NEED a protoshield. Compared to the 1-cent shield, or just a separate protoboard, a proto-shield offers a convenient platform for somewhat longer-termed projects. You can use flying wires for experimenting, a protoshield with protoboard for (say) the duration of a class project, or a protoshield with soldered components for a semi-permanent project (like an art exhibit) (note that most protoshields include a copper pattern that mimics a protoboard, so it's comparatiively easy to transfer a circuit from the protoboard to a more permanent state.)

For a truly permanent project, and especially for one made in quantity, you'd probably want to have a PCB made, but the protoshield excels in providing less difficult "transition" steps.