Need idea for a robot "hand"

[tailsmastermind]

Okay, at my school, we are contructing a robot for compition. It need to be able to lift 4 large batteries (D+ I believe), 4 2x4 legos, 4 ping pong balls, and 1 tennis ball. The robot does not need to lift all at once and it also must be able to lift it up into a standered 11.5 ounce coffe can. Now this would be easy except for one thing. We only have two extra ports to work with. two are being used for driving, and sadly, we only have a 4 port connecter and can't get a better one due to budget cuts for our school. Now I know there are (some) intellegent members here, so I was hoping if I could get some ideas.

 

[Kaysakado]

I have the felling this one of those Lego League things, but anyways. You have two more ports, right? Which means two more motors, right? If so, look at this diagram:

__+
_/ \
    \
     \
      +

Plusses are the motors.

 

[tailsmastermind]

I thought about that, and I'm not sure what you mean for it to do. I decided that it is a little hard for you to know what to do if you have no clue what the robot looks like.
Here is an MS paint picture of it.

I colored part of it so you know what does what. The yellow one goes to nothing, so don't worry about it. The object on it's back is what is used for turning/moving forward and backwards. I only showed that the third port is used because it is currently used to lift the handly from last year. I can't give you a better picture than that since my teacher has the car right now.
Also, if anyone has any ideas to attach the can to the back of the car, please say so.

 

[Kaysakado]

You use the red port to move the arm up and down, and the yellow port to open and close the hand. Simple. =\

 

[tailsmastermind]

That makes sence. I couldnt really tell what angle I was looking at from the picture.