Should I buy an iPad or an iPhone?

I currently own an iPhone 3gs (16gb) and an iPod 4th generation (32gb). I'm unsure whether to upgrade my phone, or to purchase an iPad. What are your thoughts?

Added (1). It was probably worth mentioning I only have enough money for one, not both.

IPad

To hell with it get both

Get the iPhone because it can basically do everything iPad does

Iphone

I pad amazing stuff

I would personally get the i phone 5. The i phone 5 is almost practically an i pad without the big screen.

Depends if you want to make phone calls or not. My opinion would be that 3GS is quite old now so I would upgrade to 5.
You can recycle your old stuff on apple's site and they will give you store credit for it, so at least you will get something back for it. Even if damaged something is better then nothing.
http://www.apple.com/...recycling/